muscleSS00

Ok I am getting an SES that says lean in both banks that comes and goes even after the long tubes and o/r y. Auto Zones said it was the O2s the 4th time I had it cleared. It will come on and then go away sometimes! I put on hte stock maf and cannot figure it out. Any ideas out there, its been doing this for 5 months now?

Slowhawk

iTrader: (12)

Have you checked for airleaks in the intake?
Any tuning?I found that 00 cars run rather lean with any mods.A MAFT could fix your problem.

muscleSS00

does a maft let you know if your rich or lean? What is the best way to check intake for leaks?

Slowhawk

iTrader: (12)

Most of the time you can hear air leaks.The common one is around the fitting for the EGR tube in the intake.Just start the car and spray WD-40 or carb cleaner on the intake at the tube.Idle will change if there is a leak.Check all pieces from the Mass air to Throttle body too.Any leak there will do it.
A MAFT can add fuel fixing a "lean condition"

Also if there is any exhaust leaks from the headers to the Y-pipe,that can pull fresh air across the 02's causing lean.

Flyer

iTrader: (1)

I threw lean codes and misfire codes (from fouled out plugs) when I put my headers on running them open for the weekend. I also went through 2 sets of plugs while my stft's were showing +55'ish.

Once I got the exhaust welded up, all was smooth. Fresh air on the o2's will make the pcm go crazy ...