I just replaced my O2's with AC ones and it was doing it with my old ones as well, so I don't think it's 02's. It did it before the wires, headers, and programming just as bad so I don't think it's any of those. My MAF and CAI were about the only thing done when I got the car, which leads me to the MAF causing it. When I had Bryan do the programming I had him adjust for the ported and descreened MAF. I think it's running too rich at idle because when it's colder or night comes it's not as bad. By colder in Florida I mean 50's or 60's versus 80's when it's worse. I know from racing two stroke four wheelers that 10 degrees can make a difference but I didn't think in a 4 stroke car engine it would. Any way to lean it out at idle besides programming the PCM? I'll pull the plug on the MAF tomorrow and see what that does. As far as what Momar said, I have no clue.

 

Well, I unplugged the MAF and it idled smooth. So I guess my problem is with the MAF or is there other sensors that are closed when unplugging the MAF. I'm going to try to clean the little resistors and bars on the MAF and see if that makes a difference. When I ported it and descreened it, I took it apart and never touched the bars so I don't think there damaged. I really don't want to buy a new MAF. I don't know anyone to swap with to try a different one.

 

Actually, come to think of it... when I first installed my headers (2 years ago), I noticed that I was getting arough idle. I looked and replaced almost anything I could think of. I had not other driving issues other than at idle.. which was pissing me off. It was also intermitent... depending on environmental conditions, it was either better or worse.

As a last resort, I then switched the MAF housing from the ported one to a stock one with screen. (I kept the same MAF sensor)

The problem amazingly went away.... I still, to this day have no clue why this is.. may the turbulent air was doing someting... but not sure since it never happened b4 the headers.