I've had this problem recently where the RPMs will drop and then immediately rev with the traction control turning off. It does it when I'm idling and driving. It seemed like a MAF problem, so I replaced it and the IAT sensor, but that didn't solve it. There's some variation in the RPM hiccup. Sometimes it revs higher, sometimes it feels like it's going to die for a split second. On a few occasions, the AC has stopped working, too - the compressor wouldn't kick on. This is not very common, though.

Any ideas?

 

It sounds like a bad tune.

 

The street tune is nearly two years old. Why would it start acting up in the past six months or so?

 

Did you check for any computer codes? Check for vacuum leaks? Why it's acting-up is unknown at this point, but I know when the tune is off, the idle will do exactly what you describe.

 

And when I'm at highway speeds?

Occasionally, the SES light will instantaneously flash, but one time I took it to Autozone and they said nothing was registered. I'll poke around for a vacuum leak.

 

It seems that it acts up more in warmer weather. Here's another question. Do you think that a simple retune would fix it? I'm trying to get in touch with the guy who did my street tune. Or could it be a hardware (PCM/ECU) issue? This would be much more of a hassle. The car otherwise performs just fine outside of these hiccups.

I know that I don't have any significant data points to add. I may just buy a damn code scanner later today to have instead of having to go to Autozone whenever I need to pull a code. The SES light is not on now, but it momentarily flashed earlier when the car acted up.

 

Oh, nice. I just came across this.