Well, This is definatel off-topic that'* for sure, my friend has this car, it'* a '95 Chrysler Intrepid 3.5 DOHC. He is having a over-reving problem like 1800-2000 RPM all the time, we replaced the timing belt, timing belt tensionor, water pump, all gaskets, timed it properly. but it always over-revs. The computer has been reset, I don't know if this is a sensor or what? Anybody anything? thanks for the help guys!
The lower intake manifold gaskets probably. Try checking them for leaks. A little carb cleaner sprayed in the area usually does the trick...if your idle changes after you spray, you know you've got a leak.
The first place I would look is in the throttle linkage; is the throttle closing all the way? (I just went thru this on my Sable starting at 1500 and ending up at 3000 by the time I got home) As you work the throttle from under the hood (engine off) let it snap back; if you don't hear a metal on metal tap from the setscrew hitting the stop odds are your TB isn't able to close all the way.
Next up is testing the Idle Air Controller. Try taking it off and cleaning the insides with carb cleaner. Ohm out the ectrical portion of the IAC but I don't know what the spec is for that. I would recommend cleaning the throttle body while you're under the hood and lubricating the throttle linkage. The IAC was my problem.
Next I would check for vacuum leaks as suggested.
BTW - Has he had this in for the recalls? Injector O-rings and control arm bracing iirc. Mine was totalled on Christmas eve '05
98 SSEi 111,222 miles.
Intense PCM, LS6 Valve springs, PEMS, FWI. Hawk Street Pads.