Last night while sitting in traffic I noticed the idle started to increase gradually. Eventually I had to put the car in neutral because it was really trying to move on its own-idling at 1600 RPM in gear. Once in neutral it idled as high as 2600-2700 RPM. I finally got out of traffic, and drove some freeway. Once back onto secondary streets-it was idling fine again.

Any ideas as to why it was doing this?

 

vacuum leak?
ECU hiccup?

 

Sounds like the TPS or IACV was acting up.

 

hmm...thanks for the replies guys.

No CEL came on btw. Hope it was just feeling moody after sitting for a week.