Lately when I have started my car, the engine revs up to about 3500 rpm and stays there until i put it in gear. When im idling at a light and put it in neutral or park once it has been running, the issue goes away.

Anyone have a clue why it might be doing this?

Oh, and also, another oddity: when i give it a little bit of gas in park or neutral, it will rev up, but when the RPMs drop back down to about 1500, it revs again slightly before dropping back to idle.

 

This happened to me also, when car was cold only. After driving and then having a moment for the car to sit off, it wouldnt do it.

 

Air bypass valve staying open?

 

wouldnt surprise me if that's it. I have a check engine light on, but the only code there is for the O2 sensor. I may just have to break down and swipe another one out of the junk yard. are they the same for the turbo and non turbo?

 

I would think that idle problem has something to do with the idle control valve. When you start the car, tap it with a screw driver and see if it drops.

On the O2 sensor, I think so. You can check FCP and look at the part numbers.

 

no i meant are the idle control valves the same for the turbo and non turbo? I have O2 sensors already - just not putting them in until i put on my new turbo and exhaust.