check engine light code

**cant.b.caught.z28** · 07-11-2009, 08:37 AM

I just got my camaro back from having my rear end rebuilt, and changing the gear/pinion to 3:73... and later that evening after driving around for a bit my check engine light comes on... the codes are:
fuel trim bank one condition, and fuel trim bank two condition...
it says the powertrain control module uses the oxygen sensor to calculate the air./fuel ratio of the engine. the computer has recognized a rich or lean condition on one engine bank only... then it also says the ecm has detected a rich or lean a/f ratio condition on bank two.
probable cause: if bank one and two are set together suspect a fuel pressure condition or maf sensor fault, failed o2 sensor, ignition misfire condition, or fuel injector problem...?

Has anyone else had this problem, and if so could you please help me out a little on what i should check?

additional information: I have a walbro 220 fuel pump in the back, slp MAF, have replaced the fuel injectors a year ago, and i have replaced the fuel filter as well. I'm leaning towards it being an o2 sensor, but I will be getting headers soon, and taking the car to a dyno shop here to get it tuned, and to have my speedo reset for the gear swap.. so if its the o2 should i just wait to fix it?

**64MonGooSe64** · 07-11-2009, 03:32 PM

Its possibly your SLP MAF, our cars have a previously tuned set up to work with our stock MAF's, being an aftermarket MAF you would think it would read the same as our stock ones but it doesnt and with a stock ls1 the only gains you will see with the SLP MAF will be about 5 hp, but its created throu the motor leaning out due to getting false reading from the MAF, theres a good chance this could be throwing ur ecu off.

just a quick question, is the reading coming from the emissions sector, which would most commonly involve o2's or egr, or are you getting a manufactoring code.

**sunsetorangess** · 07-11-2009, 05:34 PM

Put a stock maf back on and sell the SLP maf to anyone that wants it unless your pushing upwards of 500hp at the wheels.
The stocker will work fine.
J

**DaddySS** · 07-12-2009, 01:39 AM

I would reset the PCM to clear the code, buy your new 02 sensors but don't install them until a day or so after you put the headers on. New headers are notorious for fouling 02 sensors and I always recommend running the engine with old 02 sensors - at least for the first full heat up of the headers.

**cant.b.caught.z28** · 07-12-2009, 08:24 AM

Originally Posted by 64MonGooSe64

Its possibly your SLP MAF, our cars have a previously tuned set up to work with our stock MAF's, being an aftermarket MAF you would think it would read the same as our stock ones but it doesnt and with a stock ls1 the only gains you will see with the SLP MAF will be about 5 hp, but its created throu the motor leaning out due to getting false reading from the MAF, theres a good chance this could be throwing ur ecu off.

just a quick question, is the reading coming from the emissions sector, which would most commonly involve o2's or egr, or are you getting a manufactoring code.

Well I've had the slp maf for over a year now and never had a problem with it before..?
and i'm not sure what you mean by the emissions sector or manufacturing code? I just took it to auto zone and had them pull up the codes and print me off a list..