i have an 03 wrx, i just bought it not too long ago. it runs great, drives great, but i keep getting a cel. it says: p0171 system too lean(bank1 or something)
it has a cold air intake, i took the lower part of the pipe off and basically turned it into a short ram. i changed the air filter, when i changed the filter the light came on(same code p0171)... i disconnected the batt and reset the ecu.. when i did that, i also took the hose off the BOV, and plugged the hose.

no light came on, but the car didnt react well at crusing speeds and part throtle condictions, so i decided to hook the BOV back to the intake.. ever since then i have that damned light on..... i tried erasing the codes with an obd2 scanner. and tryed disconnecting the batt(left it disconnected for 30 mins) and still the light comes back on....

how do i make it go away... if its too lean shouldnt the ecu compensate for that..
a cold air intake shouldn't through things that far out of whack that the ecu cant keep up or can it?

 

cold air intakes are bad for your car.

get a short ram, or just do a drop in, on most setups, you won't be able to notice the difference

 

No,intakes in general are bad for theses cars if you have one that does not retain the factory inner diameter size for the MAF housing .Not just cold air intakes.Go back to the stock box.
http://www.ecutek.com/tuning/induction/
http://www.cobbtuning.com/tech/intakes/

 

i dont have the stock air box, i bought the car used and it didnt have one..
the pipe coming off the turbo is stock, then after it comes out from underneath the intake manifold is where the cai starts, it starts where the mass air flow sensor is, its an 'S' shaped pipe thats 2.5 inches in dia. i wish i had the stock box to put in but, i don't. any other ways to solve this problem?

 

I had the same problem with my car because of the downpipe. The O2 sensor was getting a reading so i was getting the horrible Cruise control light. I dont know what the problem is with your car but I have a Injen wrinkle red CAI, HKS Turbo Back system and after the CEL fix it maybe came on once. I learned that I should just warm the car up for like 30 seconds and its all good. Here is the CEL fix I did. You have nothing to lose, it only cost 8 bucks max. Check it out:

http://forums.nasioc.com/forums/show...96&postcount=7