Have a 97 Camaro Z28 with LT1 stock engine. Had the SES light come on, had AutoZone let me pull codes and got the P0171, P0174 which are the Lean codes for both banks. Also the P0507 which is Idle Air Control (IAC) System RPM Higher Than Expected. The car starts fine, but when it is at idle, it will jump back and forth from 900 to about 800 and shakes, not violently, just feels like it's going to stall. Guy at AutoZone said it was probably the MAF. I took it out and cleaned it with some MAF cleaner, also cleaned the Throttle Body while everything was off. Got everything hooked back up and still same problem. Ordered a new MAF and it's on the way. Just wondering if there is anything else I should check and try.

 

Found out there was a pretty good size vacuum leak. The boot at the 90 degree angle to the PCV valve was pretty much gone. I've since replaced that and it helped quite a bit. No more SES light, but there is still some of the problem going on. Not nearly as severe as before, still will go up and down only about 100 RPM and shake as it goes back up. Only happens at idle when in Drive, sitting at redlights is most noticeable. Thinking maybe IAC valve, but not sure. Any help??