2500 rpm idle when getting off highway.

I have an 03' cavalier with a 2.2L ecotec, when i get off of the highway my engine idles at around 2500-3000 rpm's when i push in the clutch and when i am in neutral. what could be the cause of this problem? There is also idle surge sometimes when i am stopped and in neutral/push in the clutch. there is a thread about this happening to 02' cavaliers but i don't know if it could be the same electrical connector that connects the engine fan to the engine. is this generally the same problem?

'02 and '03 are nearly identical, check that first. I don't see how a fan connector could cause it to idle high, but who knows.

Otherwise, check the IAC motor/valve. It opens more the faster the engine is going to keep it from dying if you suddenly let off the gas. If it's sticking or moving very slow, it could cause your problem.

I heard with newer motors, when you are coming down in rpms, the motor will compensate when there is to much fuel, or something in the motor. So it will keep the revs high in order to burn off what it is sensing. I dont have facts to back it up or anything, but its some info to possibly investigfate