Car bogging at full throttle off the line

[Baddog]

If I punch my car right off the line the car lunges forward and chokes then catches and bogs again and again till I let off. Any ideas as to wtf is causing this? I am going to be getting headers and a track pipe soon. Could clogged cats cause this?

Automatic
180k
2.2
Hybrid Intake, No CAI or SRI

[Huffer]

Has it always done this or is this the first time? Autos are not designed for hard launches unless you restrict the gearing to 1 or 2.

[Baddog]

This is fairly new. Regardless of the gear I am in it wont "launch" it will bog. My ex-girlfriends 92 LS with the 4EAT can take off the line like a bat out of hell with 200k on the clock.

[Baddog]

Anyone?

[Wiscon_Mark]

If you don't know the last time your transmission has been serviced, get the fluid changed.

Check any kind of fuel delivery issues, ignition issues, or airflow issues. Especially make sure the MAF and air filter are clean and do plugs if you also don't know when the last time they were done was.

[EJ22E]

Try replacing your knock sensor. Mine bogged down at launch. Replaced the sensor and it had full power afterwards.

[Baddog]

Knock sensor is maybe 6 months on.

Trans was serviced with Castrol Multi Import ATF about 20k ago.

Front diff looks a little low but thats about it.

Hybrid intake with K&N. All intake hoses are there and attached. MAF is clean. Plugs and Wires were done around 15k ago.

Fuel Filter has been replaced. Has an MSD Coil

[httrdd]

No sure if I told you this yet, but it could be your Maf. Sometimes the solder joints start breaking and causing a bad connection. Swap in another Maf. Hell I have one I can sell you cheap.

[Wiscon_Mark]

Oxygen sensors would probably throw a CEL, but your front one not reading properly could cause some A/F issues that may lead to bogging. It really sounds like you've covered all the main bases. Have you tried running Seafoam through your intake and gas tank?

[Baddog]

I have fed 1/3 of a can of Sea Foam through the PCV valve. And half a can through the gas tank. Also have used Lucas Fuel Injector cleaner every 4-5k miles.

[Baddog]

I will try another MAF from a friends car. IF that's the case I will be in touch with you HTTRDD. I will be getting a new O2 sensors just in case. Getting headers and a new mid pipe made.

[GTDrifter]

This happened to my GT with a 2.2 swap...after time it bogged even at light throttle and turned up to be the fuel pump being bad...when it was occurring I replaced 3 4 knock sensors and 1 maf unit with no success.

[Baddog]

How can I test if it's the fuel pump? The car drives fine other wise.

[GTDrifter]

my cel was on as well and said it was an issue with the fuel delivery system...is your cel on?

[Baddog]

No CEL

[Matty2Hotty]

Hmmm am having this problem too, wot or even light throttle she bogs down. Once I get up to about 3000k she kicks in feeling like I just hit boost on a car. Debating on buying a new MAF or TPS sensor, just got a new front o2 and knock sensor.

[Baddog]

O2 sensor and Knock sensor didn't help?

My TPS is new (maybe it needs to be calibrated professionally?) and I tried testing a different MAF and it didn't change anything.

And I know what you mean. Hit 3-3.5k revs and boom she takes off

[Matty2Hotty]

Pretty much exactly like this link... It's like wtf, someone has to have a answer.
http://www.justanswer.com/subaru/5kkh4- ... 0-rpm.html (http://www.justanswer.com/subaru/5kkh4-subaru-legacy-1999-sugar-legacy-no-power-till-3400-rpm.html)

[Huffer]

Hit 3-3.5k revs and boom she takes off

Are you WOT at 3000-3500rpm? Or are you just holding the pedal there?

If you're WOT, then the issue is with the open loop tuning, when you mash the gas the ECU switches over to closed loop.

[Matty2Hotty]

I'm like light or wot throttle from stop idle untill it reaches 3k+ untill it gets going. If I reset the ecu or pull the battery it runs perfectly fine for a good 10miles or so and goes back to this again.

[Baddog]

I'm like light or wot throttle from stop idle untill it reaches 3k+ untill it gets going. If I reset the ecu or pull the battery it runs perfectly fine for a good 10miles or so and goes back to this again.


Same here. It's like something is wrong and then when the ECU re-learns and notices that something isnt right it starts to slow down.

Huffer: It's at any throttle. If I go half throttle it feels like something is holding the engine back and then it frees up. I wonder if my cats are causing this. Because I have a nasty smell when I give it more then half throttle. ANd it smells like rotten eggs.

[Matty2Hotty]

Rotten eggs is a cat issue. I'm not noticeing any smell though.

[Baddog]

As I replace stuff over time I will post here. You should do the same. I am very curious as to why it's this way.

[still_alive]

Hit 3-3.5k revs and boom she takes off

Are you WOT at 3000-3500rpm? Or are you just holding the pedal there?

If you're WOT, then the issue is with the open loop tuning, when you mash the gas the ECU switches over to closed loop.


I'm having that same problem..if it is is the tuning how would I fix that Huffer? can you elaborate? Lets try and track it down like this..what does everyone having this problem have done with their exhaust/cats/header?

I have an UEL header with gutted second cat, o2 spacer on the rear sensor, no resonator, and a straight thru style muffler

[Matty2Hotty]

My car is 100% completely stock intake to exhaust

[Perdue]

My outback had the same problem but rarely threw a code. When it did, it ended up being for the knock sensor. My other thought, if your maf is clean and you have no CEL, is an exhaust leak close to the head, but you would definitely know about that.

[still_alive]

hmmm I think I do have a small exhaust leak. But it wouldn't cause it to feel like that would it? Its like Matty2Hotty said, it feels like I'm hitting boost in a N/A car

[Perdue]

when my Borla headers broke on the first car, they did something similar. I don't know if its the total loss of back pressure or what. I'm just throwing ideas though. Seems like yoy have covered a lot of other stuff.

[Matty2Hotty]

Ingnition timing 15 at 700rpm .32 air flow rate

Ignition timing 35 at 3000rpm rev with 4.00 lb/min air flow rate

Short trim fuel -2-4percent idle
Long term 3.9 idle

Map sensor 8 in.hg at idle
24 in.hg at 3000rpm rev

TPS sensor 0% idle and changes when I do rev.

Reading off my scanner in park. It's seriously just weird, highly doubt a exhaust leak would cause this. Might try a new tps sensor since it does relay to the ecu. Seems I can get a little back fire revving and letting off and revving. Hmmmmm

[still_alive]

The TPS sensor is supposed to have 0 resistance with the throttle cold/idle and infinite resistance when open.
...is there anyway you can monitor air fuel ratio when driving to see if it spikes or something around 3000rpms? like maybe it is putting too much fuel and it all the sudden catches up with the demand for it.

When my exhaust was stock I could get it to pop and backfire when revving, maybe like I'm thinking it's dumping too much fuel in prematurely?
just some thoughts

[Matty2Hotty]

I don't think my scanner had that option on the monitor. Haven't tried to plug it into the laptop to check. I did notice my fuel sucked down pretty quick from driving it. I did get a new Bosch front o2, maybe should get a new denso front and rear combo.

[still_alive]

My fuel seems to disappear too, did the new front o2 sensor help at all? I think that's the only one that controls the air/fuel ratio through open and closed loop.
If someone could watch the air/fuel ratio while driving and tell us the findings it might help

[Matty2Hotty]

New o2 didn't help at all, Previous owner did weld a new front cat and welded where the flange was to the rear cat and I saw a crack in the welds so am in the process of ordering the correct front/rear bolt on replacement cats along with denso oe front/rear o2 sensors to sweeten the deal on finding this problem.

[Matty2Hotty]

Okay the tps sensor as testing once I get up to about .38ish volts on up I get a humming really loud from somewhere like the tranny or some unit I can't pinpoint, rotate the sensor back down it goes off. Any help what is going on?

[Cwebboutbacked1]

had the same problem with my first 98 l, it was a knock sensor, weird how bad it affected the car, i bogged down randomly in random gears

[Baddog]

My knock sensor is new. Didn't do much for me as far as bogging goes.

Fixed the CEL though.

[still_alive]

its not so much bogging as much as it feels like boost kicking in

[Huffer]

Have any of you cleaned your butterfly throttle plate? The plate that opens/closes when throttle is open/closed? Sometimes that gets gunked up and can cause issues. Also, check for any slack on your throttle cable.

[Matty2Hotty]

Yup did all that, debating on buying a whole new throttle body with sensor off a wrecker for $80 and see if that fixes my issue as maybe my tps sensor is shorting something out. It sounds like its a humming/electrical short by the tranny. Did a grounding mod too and no change.

[Huffer]

If your TPS isn't working right, you can just swap the sensor - you can test it for continuity too.

[Matty2Hotty]

Well I was getting a perfect reading of .45-.48 and 4.28 volts wot testing it but got this nasty buzzing sound, someone said it might be the o2 sensor, etc, or solenoid in the tranny.

[still_alive]

same thing here, cleaned my throttle body before and the first thing I did when I bought the car was tighten the throttle cable...kinda running out of ideas?

[Baddog]

Cleaned the plate on the TB before with carb cleaner. TPS is new.

Tightend up my throttle body cable as well.

And to the comment of boost kicking it. That's what mine feels like too. All the sudden it just gets this surge of power and starts pulling

[Matty2Hotty]

Well I found some nasty cracks in my first cat at the welds and the previous owner welded the first cat to the second cat section, ordering new denso front/rear o2 sensors will all gaskets. I'm really thinking this might fix it.

[Reason]

It may be a fuel issue, I've had the same issue with all my Subaru. Everything I tried never really help. I think when you mash the gas the EDU isn't sending the correct amount of fuel at the right time. Fuel pressure could probably fall below the desired pressure too. And who knows it could be more than one issue at play I don't really know.

[Matty2Hotty]

Got a but load of codes... Put the tps into spec at .46 idle and 4.29 wot testing, won't buzz but will testing wot with the throttle body. Hooked everything else up and started her up. Check light read 5 codes now.

P0122 throttle switch A low imput
P1510 powertrain
P1512 powertrain
P1514 powertrain
P1516 powertrain

[MarkSubi]

I'm glad yawl have this thread going. My leggy Is doing something like this as well if I'm reading everything right and its been fine for the longest but I got home an hour ago but was on the road for three hours straight earlier and when I was half way home it started to act a little funny while driving and while at take off and while at idle my car was also kind of almost revving on its own almost but very lightly and yes even kind of jerking while doing that and only like once or twice at different times the rpms did move up but just barely from 0 to like barley anything. Idk whats going on but I just don't want it to be anything major. I'm finally having the chances coming to get my car the way I want it in how it rides and also in cosmetics and if this is something thats going to take a bit of money to fix then yeah, I wont be a happy camper.

[Matty2Hotty]

Well Im almost positive there is a short or bad ground in the harness($200 new from Subaru) after reading couple outback members replacing their 11 year old harness, bending wires and unplugging/replugging seemed to fix it for now as she isn't throwing any codes and driving perfectly fine. Seriously just werid, so am getting my 2.2 rebuilt next week I might as well order a new harness.

[MarkSubi]

If I punch my car right off the line the car lunges forward and chokes then catches and bogs again and again till I let off. Any ideas as to wtf is causing this? I am going to be getting headers and a track pipe soon. Could clogged cats cause this?

Automatic
180k
2.2
Hybrid Intake, No CAI or SRI


My car is doing something like this to but I'm not always taking off hard but at times pressing the gas at normal speed to but one other thing that my car is doing besides that is at idle sometimes it’s like bogging and revving on its own a little and the rpms hand kind of moves on its own but just barely and while doing that at times when bogging almost sounds like it’s going to stall. Also at times its revving high at idle to. It started doing this Friday. My subie was already acting weird to where at idle my car would stall but this barely happens anymore.

[bulldozer24]

wow this must be a common thing, i have the same problem with mine also it stumbles over itself while sitting in traffic, i thought it might be a dirty iac valve but now after reading through this i wonder if it could be the crank position sensor. Any ideas?

[MarkSubi]

wow this must be a common thing, i have the same problem with mine also it stumbles over itself while sitting in traffic, i thought it might be a dirty iac valve but now after reading through this i wonder if it could be the crank position sensor. Any ideas?

Yeah mine does that to! lol and same, I can't see it being anything else but in the electronics somewhere but who knows right now.

[Matty2Hotty]

Yeah not sure, after resetting the codes they haven't came back. Car drove 100% like new again for a good 10-20miles and back to this bogging(no cel). FML.

[MarkSubi]

I'm really trying to think what it could be because for awhile now my car would randomly stall at idle and also act like it wasn't going to start at times but that hasn't happened for awhile but everything I brought up thats happening to all of us it seems just started last friday. I was on the road for three hours straight and while being half way home is when the bogging and revving at idle on its own started up and now has been doing this ever since. the revving at idle doesn't always happen but not saying it never does.

[MarkSubi]

I Just had a super crazy thought lol but what if whats happening to our cars is caused by a part that was actually defected and this is all caused by a recall that never happened. I know were subarus as in the best but still. idk i crazy mind thinking about it :P

[Baddog]

Yeah it completely f***s my mind. I still have yet to figure it out

[bulldozer24]

have you checked the spark plugs, they can tell you a lot about your engine

[MarkSubi]

have you checked the spark plugs, they can tell you a lot about your engine


No I haven't checked my plugs but is anyone else's legacy also ideling at a high or higher rpm then its suppose to? Mine is doing that as well.

[Matty2Hotty]

But she revs perfectly to redline in park or neutral.

I just put in vpower ngk not too long ago so I know that's not the problem, plugs looked normal.

[MarkSubi]

Yeah I don't think it has anything to do with plugs, starts up fine, I also put NGK plugs in my car but that was back in 09 a few months after I bought my car so it is worth a shot but from whats going on I don't think my plugs are the problem. I plan on checking my MAF and my knock sencer sometime because I checked all the plugs and they are fine as far as I can see. I just wish I had another leggy or knew one that I could get the parts off of to try those things and see if it could be that.

[bulldozer24]

i changed my spark plugs yesterday, they seemed to help a little, the old ones showed signs of high speed glazing.

Ive also been having problems with my egr system, but i don't know if that could cause the stumbling.

[Matty2Hotty]

I have a new front Bosch o2, new knock sensor, cleaned iac and maf, nkg plugs are 100miles old, new fuel filter, fuel pump was recently changed...

[MarkSubi]

I have a new front Bosch o2, new knock sensor, cleaned iac and maf, nkg plugs are 100miles old, new fuel filter, fuel pump was recently changed...


And its still bogging and everything even after having all of that!? :smt017

[Matty2Hotty]

Yup, leaving me with a bad tps, iac, crank or maf I'm thinking

[MarkSubi]

Hm. well then ill probably check all the ones on urs that haven't been checked then.

[bulldozer24]

well i fixed my stumbling issue, i changed the plugs and cleaned the entire egr system which was completely stopped up. it also helped the bogging but didn't completely cure it, just another thing for you guys to check.

[Matty2Hotty]

I bought new rallitech plug wires, new spark plugs(NGK platinum ones), ordered a used eBay throttle body with low mileage tps and iac sensors on it for $50(worth a try), got OEM denso front/rear o2 sensors, all new header gaskets on back, replacing some stiff vac lines... Installing all this when the parts come hopefully by the weekend to test them out. If all this doesn't work I seriously just spending the $100+ and taking it to Subaru.

[MarkSubi]

I bought new rallitech plug wires, new spark plugs(NGK platinum ones), ordered a used eBay throttle body with low mileage tps and iac sensors on it for $50(worth a try), got OEM denso front/rear o2 sensors, all new header gaskets on back, replacing some stiff vac lines... Installing all this when the parts come hopefully by the weekend to test them out. If all this doesn't work I seriously just spending the $100+ and taking it to Subaru.


Damn :o wish I could do all that right now and if that doesn't work ill be surprised.

&

My car bogging and what not kind of sorta stopped but not fully its still there, just doesn't happen very often but my car is still running the rpms higher then it should.

[MarkSubi]

Okay my car is kind of running with the Rpm's a little higher than it should and it hasn't done this in forever but at a point at random times very far apart from each other it would stall at idle or when driving super slow but it hasn't done it in forever but now this is the second time THIS has happened but now after downshifting while slowing down the car once I’m at a standstill its running but then like a minute later it stalls or when I’m starting to drive off it stalls. I have no clue what this is all about but I fill it may all be connected to each other in some way. I’m replying with this information right now because this is the first time this has happened to where it almost never started back up.

My car is auto and yes if I need to stop sort of suddenly I downshift while doing so, it helps big time.

[Matty2Hotty]

Have to tried adjusting the TPS? Do you get a buzzing if you have key on but not started/running if you move the TPS or actually leave it alone and just do a WOT spin on your throttle body?

[MarkSubi]

Whats a WOT spin? and nope, no buzzing noise.

[Matty2Hotty]

Turn the car fully to on position but don't start it. Go out and slowly twist the throttle body to wide open throttle by hand is what I was meaning, see if you get any buzzing or anything while turning the throttle body.

[MarkSubi]

Yup, it buzzed when I started and then I guess it was opening more because then the buzz went a little louder. Does this mean that it's all working or that something is up?

[Matty2Hotty]

I'm not sure, it almost sounds like a electrical short but someone mentioned it just might be the tranny solenoids. Just doesnt sound right to me.

[MarkSubi]

Yeah personally I thing everything that has been going on is an electrical issue, I just have no clue to what or where it is at. Where did you hear that from? I'd love to get as much info on this as much as possible.

[Baddog]

Yeah I am a getting a little fed up with this issue.

I did a 0-60 test today between my 96 Legacy and my girlfriends 92 Legacy with blown HG's. Both Automatics. Hers with 3.9 gears and mine 4.11.

I have a full headerback, MSD, new plugs and wires and all the maintaince done. Hybrid intake. I did a 13.2 to 60mph. Car weighed 2964 at the scrap yard with me out of it. I weigh 260lbs.

Hers has a 2.25 catback and thats it with old plugs. She did it in 10.3 to 60mph. Her car weighed in at 3091.

I cannot understand why this is happening...That is a HUGE difference

[MarkSubi]

Yeah this really bothers me and I just don't get how so many of our leggy’s on here are acting and doing these things but no one has an answer.

[Matty2Hotty]

Well here is the thing... My car runs, shifts and everything perfectly fine resetting the ecu. Runs 20miles or so and goes back to bogging and no throttle response at all. Pluged in my scanner running fine before bogging reads "readiness" No and after the 20 miles bogging comes back it shows "readiness" Yes, it is something going on in the none readiness phase that has to be giving some different signals to something. Just wish it would throw a stupid code without taking her into the dealer.

[MarkSubi]

How do you reset the ecu? I wonder how doing so will effect my car, beacuse its weird, does all the same things but at times it sort of seems like it fixes its self for a little bit but then starts up again.

[Baddog]

Yeah an ECU reset fixes mine too. 40-50 miles later it comes back.

Matty have you tried to do your Coolant sensor yet? I have been thinking about that

[Matty2Hotty]

No I haven't yet, I herd that could be a issue to. By now I herd every sensor could cause this.

[MarkSubi]

No I haven't yet, I herd that could be a issue to. By now I herd every sensor could cause this.

Greaaaat, -_-" that makes it easier the find.

[Matty2Hotty]

Yeah it's a joke seriously. I mean what honestly could cause the car to run perfect resetting it and once relearned change totally with no power and not throw a code. Just doesn't make sense.

[Baddog]

It's pretty damn annoying. This with my wheel shutter at freeway speeds blows my mind.

Neither of which I can figure out to save my life.

[MarkSubi]

Yeah and whats even more wierd to me is how us three and pretty much everyone else that has commented on this thread are all going through the same thing.

[winston856]

Any more developments on the issue? My car is doing the same as well and I don't know what's causing it.

I replaced:

Front and rear o2 sensors
coolant temp sensor
spark plugs + wires

I have not done the TPS yet but I have checked and set it to spec with a dmm. Also I haven't found any vacuum leaks so far either.

Have any of you considered the injectors to be leaking perhaps?

[subie/legacy]

Is everyone having this issue, have an automatic transmission?
Don't know if that matters or not, but would be odd if that were the case.

[MarkSubi]

My car has been alright but the issue is still there because it still does some of the stuff but very faint but that doesn't always happen. Ether way, car is doing well but this issue or w/e is causing it is still there.

[Baddog]

I think we all have automatics.

[MarkSubi]

lol If we all do then I think he have a big clue as to whats going on lol

[winston856]

Mine's a manual.

[tnrknght]

New to the subaru game but I also have the same issue. Since I got the car I have done plugs and wires, oil change, new air intake filter, MAP sensor, and starter. When this started happening I mentioned it to my service manager who said it could very well be a clogged cat converter, but Im starting to question at this point. I did notice that when Im low enough on fuel I get the p0440 code. I also noticed that its mainly a problem for me when the car is cold. If I start it and let it run for a couple minutes I can take off no problem but until it hits running temp itll bog down. Wasnt good trying to leave my street and being unable to move. Ill be replacing the fuel filter (no idea when it was done) and banging out the cats to see if it makes any difference.

[Baddog]

Cats are not the issue for me. I am running a new HFC.

[Matty2Hotty]

Me neither, I changed my cats(used low miles ones) but no difference. It's not o2 sensors, knock sensor, cats, spark plugs, wires, Fuel pump, fuel filter, grounding, and tps Sensor are ruled out for me.

[MarkSubi]

Would yawl think it could be something to do with the tranny somewhere?

[Matty2Hotty]

That's honestly what I was thinking... Car revs and everything perfect in neutral or park. I was leading towards something soliniod or sensor bad on the tranny.

[MarkSubi]

Yeah, that or worse, maybe somethings up inside the torqe converter.

[tnrknght]

Something I picked up from alldata.com, it helps working in a networked shop :) maybe this can help some of us narrow down this way too common issue:


NUMBER: 11-53-98

DATE: 1-05-99
APPLICABILITY:
97 - 98 Legacy, Impreza, and Forester Manual Transmission vehicles with 2.5L & 2.2L engines

Subject:
Hesitation On Acceleration

In the event you encounter a customer complaint of a slight engine hesitation between 1500 - 2500 rpm's when the engine is cold or hot, perform the following:

Eliminate all external influences, such as a incorrect or dirty air filter, loose or cracked intake duct, dirty fuel filter, low fuel pressure, PVC system, or low engine vacuum that would indicate an external leak or an internal engine component. Check for trouble codes and repair as necessary. Verify the fuel quality.

If all external components are confirmed to be operating within vehicle specifications, the hesitation may be caused by the ignition control logic in the BCM. Under certain low rpm driving patterns, the ignition control system can pick up engine vibrations through the knock sensor and may retard the ignition timing. This ignition timing is learned by the ECM and placed in memory. Note: This area of the memory can not be viewed by using the Select Monitor. When the vehicle is driven under these conditions, the timing may be retarded and could cause the engine to hesitate on acceleration. To confirm this condition, road test the vehicle while viewing the Knock Sensor Signal on the Select Monitor. If you duplicate the hesitation, and the reading on the monitor is around -10 Degrees, you will need to change the ECM to correct the concern.
Note : Some vehicles (shown on the following two charts) were produced with two different emission systems during the same model year. To identify which system you have, look at the Vehicle Identification Number. Refer to the chart to identify which system you have on the 98MY Forester and 97MY Impreza vehicles and choose the correct part number from the chart in this bulletin.

[MarkSubi]

Something I picked up from alldata.com, it helps working in a networked shop :) maybe this can help some of us narrow down this way too common issue:


NUMBER: 11-53-98

DATE: 1-05-99
APPLICABILITY:
97 - 98 Legacy, Impreza, and Forester Manual Transmission vehicles with 2.5L & 2.2L engines

Subject:
Hesitation On Acceleration

In the event you encounter a customer complaint of a slight engine hesitation between 1500 - 2500 rpm's when the engine is cold or hot, perform the following:

Eliminate all external influences, such as a incorrect or dirty air filter, loose or cracked intake duct, dirty fuel filter, low fuel pressure, PVC system, or low engine vacuum that would indicate an external leak or an internal engine component. Check for trouble codes and repair as necessary. Verify the fuel quality.

If all external components are confirmed to be operating within vehicle specifications, the hesitation may be caused by the ignition control logic in the BCM. Under certain low rpm driving patterns, the ignition control system can pick up engine vibrations through the knock sensor and may retard the ignition timing. This ignition timing is learned by the ECM and placed in memory. Note: This area of the memory can not be viewed by using the Select Monitor. When the vehicle is driven under these conditions, the timing may be retarded and could cause the engine to hesitate on acceleration. To confirm this condition, road test the vehicle while viewing the Knock Sensor Signal on the Select Monitor. If you duplicate the hesitation, and the reading on the monitor is around -10 Degrees, you will need to change the ECM to correct the concern.
Note : Some vehicles (shown on the following two charts) were produced with two different emission systems during the same model year. To identify which system you have, look at the Vehicle Identification Number. Refer to the chart to identify which system you have on the 98MY Forester and 97MY Impreza vehicles and choose the correct part number from the chart in this bulletin.


Seems interesting and sounds like it could be right. definitely should look into this.

[tnrknght]

I would hope its legit, thats the website our company pays to access in order to fix cars on a daily basis XD

[Matty2Hotty]

I was really thinking ECM cause it runs perfect resetting the car every 20-30 miles and relearns something. ECM but how do I know which interchange on my phase2 one year produced 99 legacy?

[Huffer]

In the UK, some owners have been able to relocate the Knock Sensor to a new position on the block and that eliminated the problem. However, if you follow the instructions in the bulletin, which tnrknight posted "Refer to the chart to identify which system you have on the 98MY Forester and 97MY Impreza vehicles and choose the correct part number from the chart in this bulletin."

So you'll need to look at the chart and try to figure out which system you have that is equivalent to the Forester and Impreza.

[tnrknght]

I dont recall seeing any charts or diagrams on the page, maybe there was a link that I missed. Next time I work Ill be sure to look into it. My bad! :lol:

[MarkSubi]

Hopefully the charts are somewhere there, I like that were actually getting progress on this now.

[Matty2Hotty]

Yeah I need the chart to see if I can swap a different ECM, maybe a 00-02 legacy/impeza might work since they are phase2 but they aren't MAF like mine.

[tnrknght]

Alright so I tried sending the entire link to copy and paste from my own computer, but it wont let me in the link on my computer because its not a registered workstation. When I get back to work Ill take pics of the three images on the page, and then I can post them.

[Matty2Hotty]

Thinking about it not really sure any of the links would work since I think I need a MY99 link to show what interchanges.

[jockstar]

I've been following this thread for a while because I'm having a similar problem. I have new heads on my 97 L 2.2. The car will not start without me giving it a little gas. Well it starts but dies within a second or two. In any situation of RPMs under 3000 the car bogs heavily. I occasionally have P0302 (misfire) P0440 (evap system) and rarely p1507(IAC fail safe). I always have a smell of exhaust smell in the cabin.
I have replaced all vacuum lines, put in a used IACV, seafomed the PCV and in the fuel tank.
I'm running UEL headers with stock cats, resonator delete and a straight through muffler (vibrant street performance)
There is a pinhole exhaust leak at my resonator position, soon getting fixed but I dont believe that to be the culprit.
I spoke to my transmission mechanic and he said the neutral sensor on the tranny plays a large role in the engine running properly and he recommended I try that. Hes got one for me so as soon as i find the time to install it I'll share results.

[MarkSubi]

Cool this will be a big help.

[mike-tracy]

My Mom in law's 99 Legacy SUS (4eat, ej25d) just started doing this. It makes the car undrivable, :(

[Matty2Hotty]

Well I cant totally say, I swapped in a 2.5l with new tranny. Unable to drive it yet so I can't say my problem is fixed hahaha

[mike-tracy]

Hmm. Well the common recommendations are:

IAC
TPS
Front 02 sensor
Cats
Vacuum leak
MAF
ECU
Coilpack
Plugs and wires
Leaking exhaust pre cats
Air Filter
Knock sensor - this is an interesting one not well explored. Moving this to the top of the block bellhousing may help "false knock" detection
Neutral switch - when faulty it randomly tells the ecu the car is in neutral and the ecu scrambles to go into idle mode (while you're driving down the road!!!) - mentioned but not very well explored. Not too likely since the threads I've seen say the cars usually idle well.

I have yet to see a thread where the issue is completely resolved, other than if it's something super simple like plugs and wires.
I had a similar problem with my 98 Forester a couple years back, and the place I took it to replaced the cam and crank sensors - and that worked. However, I had a CEL then (can't remember what for).

[mike-tracy]

OK so I think I got this licked. Turns out I had a bad tranny mount that was missing some rubber. I replaced the mount and crossmember with a phase I one I got in the junk yard. Seems to be running fine after 50+ miles. It would drive like crap after the first 5-10 minutes before.

https://sl-i.net/FORUM/images/imported/2012/05/CIMG0203-1.jpg
(bad trans mount - it's missing it's bushing in the long stud, letting the mount twist and distort under tension)

I also replaced the exhaust manifold gaskets (one of the 1st things on the list in the FSM troubleshooting guide).

Last but not least, the tranny is a phase II, and the engine I put in is a phase I ej25d. Why is that significant? Well the lower studs are LONGER on the phase I, and when I was under the car doing the tranny mount, I noticed that the nuts on the lower studs weren't flush with the tranny case. So I put in 3 small washers per side and now we're toit liek a toiger. ;)

My guess is the tranny mount made the most difference, but the non-flush nuts were probably a contributing factor.

I didn't reset the ECU either.

I'm so happy!

[Huffer]

Good job Mike!

[Baddog]

I have a brand new mount with a rallitek insert. This problem still is there for me. However I soon won't have to worry about it. 5 speed swap within the next month.

[Matty2Hotty]

Yeah I did my 4eat with a 2.5l swap all at once... Problem is gone for has been 300+ miles now. I'm leaning more towards something bad inside the tranny for future reference.

[Baddog]

It wouldn't surprise me. My 4EAT has 191k on it now. However the girlfriends 92 has 211k on it and has torque bind. But doesn't have this issue. It can spin the tires punching it off the line. And by spin the tires I mean chirp the fronts a little before the 50/50 split happens.

[MarkSubi]

I honestly fill for me it also could be a mount or something underneath my car having to do with the tranny because about a month ago now I ran over a big rock witch suck because my car is slammed and it went in hard on my underside and ever since then I noticed my car acting like it doesn't want to start way more then it normally did and also made the engine like come on way more as well. But at the same time with me it could be something else as well.

[Wagonista]

I had this very same problem a few years ago with my MT. I'm pretty certain it was my O2 sensor. After a few months the CEL came on for it. I think it can start to go bad long before it'll throw a CEL. After I replaced it I never had the problem again.

*edit* It WAS a long time ago. It could possibly also be my group N tranny mount.

[Reason]

I think its a problem with the automatics. When you stomp on the gas its as if it doesn't give enough or it dumps too much. I always wondered about the ECU, MAF, O2 or injectors.

[mike-tracy]

To update this thread. The problem on my mom in law's SuS came back full force.
....
So I purchased a coil from a member on here (thanks Bookem!) and installed it. My reasoning behind it was the only time I got CEL's were for missfire cyls 1-4. I start it before resetting the ecu... Same problem. It's just dumping fuel (aka it leaves a fuel mist cloud), really lugging, won't go into 4th (4eat).

So I reset the ecu, and it starts to run fine. A CEL appears. I have stolen it's wheels when it was down, so I'm left with 3 crap tires and a non-outback sized donut on the rear. But I still drive it for about 5 miles or so - past the point where the problem would rear it's ugly head. It didn't start running and idling like crap or make a fuel smoke screen, but the throttle is still not quite as crisp as I remember it would be when it's running perfectly. But it still has get up and go, and feels at least 10 times better.

There's a possibility that I killed the spark plugs (~1k miles on em), o2 sensor(s) (~50k) and cats (original to vehicle so 115k) when the problem came back - I was in oregon so I had to drive the 215 miles back home with it running so bad and getting ~16mpg.

The closest parts store that has an OBD-II scanner is 25 miles away, so once I figure out the tire situation I'll see what's triggering the CEL.

Another thing I was thinking about: On the 1st gen legacys they have black and green test connectors under the dash to read the obd-i codes. I remember noticing them on my 96 Legacy when I did the heater core swap. Does anyone know if they work the same way (assuming the 99 has them)? Or are they leftovers from the rare obd-I 2nd gens?