AmbulanceDriver

Idle in my 02 hangs at 1500-2000rpms ONLY when the air conditioning is on. Soon as I turn it off it stops doing it. Idle drops after a 2-3 seconds at a complete stop. I throw a pcm p0171 occasionally when ambient tempts get over 105*. In have checked for leaks with carburetor fluid as well as cleaned the MAF. Only mods are blackwing intake with the bigger silicone tube piece that joins the two to the throttle body and exhaust with x-pipe stock headers. I tried the idle relearn and that didnt solve it either. Does the intake mods require a tune? From my reading here I thought the car would relearn the fuel trims after time. Its been like this for 4-5 months. Only other thing I can think of maybe the 02 sensors by the x pipe are bad or just replace the maf altogether?

Patrick T Dent

Has this car been tuned? I've had similar issues caused by a crap tune, I've also seen it caused by vacuum which should be an obvious one.

AmbulanceDriver

Not to my knowledge. I checked for vacuum leaks again using smoke and found nothing.

dbgoodwin

If you have a scanner then check fuel trims on both banks. You're only getting a lean code for bank 1 intermittently, but bank 2 could be close to running lean too. If bank 2 looks fine even when bank 1 is lean or close to lean, then you're likely still looking at either a vacuum leak or possibly an exhaust leak before the first oxygen sensor on the bank 1 side.

If you're close to lean on bank 2 also, then it could be a fuel issue. If that is the case I would rent a fuel pressure tester from autozone and check fuel pressure at the rail. I believe (and don't quote me on this, its been years since I tested mine, look up the specs to be sure) that you should be around 55-60 psi at the fuel rail when key on, and when running.

Being that it drives fine and only does this off throttle though, I wouldn't suspect a fuel issue. Good luck!

AmbulanceDriver

Awesome will check those things and an exhaust leak.