downtown_ss

I have been having trouble with my 02 Trans am for a few months now and can't seem to figure out what the problem is or how to fix it. The SES light will come on after a few days of drivingand the car will start to kinda miss and run really rich and get so bad the car will start to shake while driving and cut out. When I change something out it will drive good for a few days then do the same thing all over again with the light and running bad.
Things I have tried to fix the problem is changed spark plugs and wires, changed fuel filter and fuel pump, replaced MAF sensor. I have had it on the diagnostics at GM and they came up with 3 codes....lean code, misfire code, and the MAF was bad.
They wiped out the codes and replaced the MAF again and still didn't fix it.
Has anyone come across this problem or have any ideas cause Im running out of ideas.

blue98Z

iTrader: (29)

O2 sensors would be a good start. See if they or someone with some type scanner (ie HPTuner, LS1Edit, etc) can check your ignition coils for misfire. You may need to start replacing them also.

downtown_ss

Well I have long tubes and the O2's were tuned out. I thought it might be in the ECM and something to do with the tune. I just don't get why it keeps going back to driving good for a few days in between running bad. I would think if something was going out it would eventually run bad all the time or quit running.

Detoxx03

iTrader: (14)

Only thing I can think of is the O2 sensors

kibZ28

also agree with the O2's

MIKEY'S 2002 TA

iTrader: (24)

hi, i had the same problem with my 02 ws6 after a header install. it was throwing random misfire codes and was running so rich it would foul the brand new plugs out in no time. it really wasn't throwing 02 codes. it was only fouling the plugs on the passenger side. that's the side with the misfire codes. i switched the 02's passenger side to the drivers side and then the misfires switched to the drivers side. so it turned out i had one bad 02 causing it all. replaced the 02's and the car has been fine ever since. start with the 02 sensors.

almostws6

Crank sensor...

tording99Z28

iTrader: (3)

Lean code could be a vacuum leak also. Check the PCV elbow on the passenger side of the front of the intake, see if that little rubber elbow has opened up a crack in it and its sucking air.