New Header, now problems....

[99gtlimited]

So i installed my borla replica header last weekend. Love the sound, my dad though the car sounded like a v8, haha. Anyways, now with this on my car has begun to idle very rough. It jumps up and down between 250-1000 rpm intermittently. I'm it seems to be worse when cold and still does it sometimes when completely warm. I rarely get a stable idle (used to sit at about ~500rpm). I have reset the ECU, any ideas, is this related to the increase in exhaust flow?

I also seem to smell gas when the car is idling, making me think that it is running rich...

anyone else have this kind of an issue. This is the only mod to my exhaust so far, i had to get the old one out the rattles from the heat shield were driving me nuts!

Thanks!

[xXGTBspecXx]

how long has it done it my wrx acted wierd when i did a full exhaust and after 2 days of driving it learned and corrected itself.

[Reason]

Yes after you rest the ECU put some miles on it. Let us know how it is after that.

[decke48]

after you reset the ecu it need to relearn alot of components like idle and fuel trim

[track8]

Try adjusting the idle control solonoid down once the engine is warmed up.

My car sat for a few months last winter waiting for it's new head gaskets. When I started it for the first time, the idle wouldn't stabilise at all, it did exactly what you are describing. Resetting the ECU and giving it time to re-learn had no effect. I ended up turning the idle control device down a bit so that the idle was at a steady 700-ish when at operating temp.

No problems (with that) since, even after installing the EL/header and 2.5" header-back.

[99gtlimited]

how do I do that? I've driven over 150 miles and it's still far from consistent. I want roger this resolved.

[winston856]

I installed my header with no ill effects on MY96.

Did you bump jar or otherwise interfere with the front O2 sensor in any way? I would check that out, perhaps it's time for a new one.

Changing the header should not cause any problems with the ECU, especially with a reset. Perhaps another sensor coincidentally went out at the time you changed the header.

[track8]

how do I do that? I've driven over 150 miles and it's still far from consistent. I want roger this resolved.Here is a shot of the device that controls the idle speed on my car. Its got slots to rotate it to adjust the idle speed. I just turned it down 'till the idle was stable at 700-ish. https://sl-i.net/FORUM/images/imported/2008/08/Picturesofblackpinkcar003-1.jpg

[Reason]

You shouldn't need to do this from changing the header.

[dplacencia]

I have a FULL exhaust on my car and haven't had a problem.

[rougeben83]

I have a FULL exhaust on my car and haven't had a problem.

Ditto when I was N/A.

[99gtlimited]

yeah i dunno if this is the way to go. I'm thinking possible exhaust leak now?? like one of the new gaskets has failed either at the head or where the header meets the mid-pipe. The main reason i think this is because i smell exhaust (rich with fuel) especially near the front of the car, which makes me think it is leaking before the catalytic converters.


the idle is still very inconsistent, it will jump from 250 to 1250 while sitting at a light, and further down the street it may level out around 500 for a while, but never staying at that idle speed every time i stop on a drive.

The car seems to be running just fine at freeway speeds, the fuel economy may be a little lower than before but not significant.

This is really getting on my nerves, since i live in a city, and have to deal with stop and go frequently. Anybody got any other ideas??

I think i may go buy new gaskets this week and put them in just to see if that makes a difference.

Thanks to all for your input thus far, hopefully i'll get it resolved soon.

I may try to upload a video clip of the idle and sound clip of the header to see if that helps as well.

[decke48]

edit** did the manifold gasket seal well?

[99gtlimited]

i didn't remove the o2 sensor, or even really touch it for that matter, so i don't know why that would be the problem, i'm thinking that it's gotta be the manifold gasket, most likely on the passenger side as the bolt in the head didn't seem to be set that well, as it wanted to come out when i was removing one of the bolts.


this looks like it will be my first step... then reset the ECU again.

thanks for your input

[1-3-2-4]

I was going to say check the gaskets but I figured a leak would make a sound.