I know that this thread is all but dead, however, I had the exact same problem since buying my G6 GT 3.9 Liter.
Same codes, running lean on bank 1 and 2 and MAF sensor reading wrong. I also had the traction control go on and off continuously.
I got a code reader from AutoZone and there were no brake codes or wheel sensor codes at all. Whoever owned it before me but a new cold air intake and K&N air filter on it and that was the issue. I went to a junkyard and bought a factory one, replaced it and now it runs perfect.
WOW I was at a loss. I hope this helps someone else out. I made 100% sure the aftermarket cold air intake did not leak, but it made all the difference in the world. These 3.9s are not meant to run the chrome pipe air intakes. I don;t know why, but it does.
Killroy134
Same codes, running lean on bank 1 and 2 and MAF sensor reading wrong. I also had the traction control go on and off continuously.
I got a code reader from AutoZone and there were no brake codes or wheel sensor codes at all. Whoever owned it before me but a new cold air intake and K&N air filter on it and that was the issue. I went to a junkyard and bought a factory one, replaced it and now it runs perfect.
WOW I was at a loss. I hope this helps someone else out. I made 100% sure the aftermarket cold air intake did not leak, but it made all the difference in the world. These 3.9s are not meant to run the chrome pipe air intakes. I don;t know why, but it does.
Killroy134