96 legacy hard on gas

[pamike]

it's been like this for a while. it has the 2.2 motor with just under 200,000 on it. it gets horrable gas milage and it's really bugging me now. i also noticed that in the morning when i start it i can smell fuel like it's dumping raw fuel into the exhaust. no check engine light except for the occational p040 or whatever number it is. u guys know the one i mean :grin: i can go easily 5 times farther in my other legacy than i can in this one on the same amount of fuel. what i need to know is if the oxygen sensor or some other sensor can cause this or am i looking at a bigger problem?

[Wiscon_Mark]

Well, you should pull that code and tell us what it is, because we don't know what you mean. And what kind of gas mileage are you actually getting? What kind of driving are you doing? Have you run fuel system cleaners or is it due for a tune up? Bad plugs with poor spark can definitely cause you to have more a lead foot to get comparable power, hurting fuel economy. That "raw" fuel smell when you first start a car up is normal, but should go away quickly after running it for a few minutes.

Before you throw any parts at it, the CEL code (occasional or not) is important to know.

[pamike]

Well, you should pull that code and tell us what it is, because we don't know what you mean. And what kind of gas mileage are you actually getting? What kind of driving are you doing? Have you run fuel system cleaners or is it due for a tune up? Bad plugs with poor spark can definitely cause you to have more a lead foot to get comparable power, hurting fuel economy. That "raw" fuel smell when you first start a car up is normal, but should go away quickly after running it for a few minutes.

Before you throw any parts at it, the CEL code (occasional or not) is important to know.

the acctual code is a p0420 catalyst effediency below threshhold, which from what i've seen is very common and it only throws it every now and then. it's probably been 6 months since it's thrown the code and it's currently not throwing any codes. i've seen of using a spark plug anti-fowler in the rear o2 sensor to make it happy. i run fuel system cleaners from time to time the last one being about 2 weeks ago. plugs are not bad. they are ngk's and are fairly new. i currently own 3 subarus and have owned others in the past and i've never smelled the fuel smell. can't tell you the exact fuel milage as i don't normally make a habbit of checking it. all i know is when i put the same amount of gas in my other subaru's i can go way way farther on the same amount of gas. even my stage 2 wrx is way better on gas. what i need to know is what can cause horrable fuel mileage? i mean as far as sensors go or somthing thats not routine maintance. and it's not my driving style either.

and i'm 99% sure it's not leaking fuel as i've never seen anything wet under the car

[Okin DaVanh]

Tho I'm not saying these are your problems, but I'd check :

Connections to O2 sensors. A manual would be nice to have handy for the readings you should be getting for your sensors.
Knock Sensor
Fuel and air Filter for obstructions
Condition of the charcoal canister


and just for the sake of looking........ fuel filler neck.

[pamike]

Tho I'm not saying these are your problems, but I'd check :

Connections to O2 sensors. A manual would be nice to have handy for the readings you should be getting for your sensors.
Knock Sensor
Fuel and air Filter for obstructions
Condition of the charcoal canister


and just for the sake of looking........ fuel filler neck.


fuel filler looks ok. i didn't see any leaks. fuel and air filter are good. i'll have to look up the readings for the o2 sensors, acctually somone else told me it's possable it could be the o2 sensor but i didn't know how to check them. and how do i check the charcoal canister.

[Okin DaVanh]

....and how do i check the charcoal canister.



I was suggesting visually.

Should be located under the rear of the car just behind the wheel well opening in the rear. IIRC, it's on the driver's side.

I'm going to go ahead and say I believe the O2 sensor is on it's way out or your converter is.

[Wiscon_Mark]

I know people with hi-flow cats sometimes get that code, but it can also happen if your cats are clogged and flow is getting restricted. That could definitely kill gas mileage.

[pamike]

if the cat was clogged wouldn't that cause power loss? if the cat is the problem where would i get a new one without spending a fortune? even if it's aftermarket i'd want somthing that bolts into the stock location.

[Wiscon_Mark]

Yeah, but if it clogs slowly, you may not notice the power loss, and be slowly putting your foot down harder for the same power, using more fuel. I'm sure if you were to replace a good cat with a clogged one, you'd notice it, but if it slowly happens, I bet you probably wouldn't.

And it's not like the EJ22 is that powerful to begin with :lol:

[chrish8r]

i have a 1999 legacy 2.5L and am getting like 15 or 16 mpg......ive used STP cleaners and even Seafoam....what can i do to get the gas mileage i see everybody else with these cars getting???