I have a stock '99 Neon RT with a very high idle. My computer code said that there was a short in the IAC or a vacuum leak. I have no vacuum leak and replaced the Idle Control Valve. I'm still idling at around 5000 rpm. I have also replaced the TPS and MAP sensors without any luck. If anyone has any suggestions I would appreciate it thank you.

 

i think that reading can only say that there is a short in the IAC circuit. i have the same problem on my honda civic (1988) and am suppose to have power to both wires going into the IAC (not the case where they are positive and negative). i have no idea if your dodge is like that.
and my problem is only in the winter.

have not completed tracking it down, but pretty sure that it is the ECU. there is a place in texas that repairs them, just wish they were still in austin.

your problem may also be in the ECU.

 

I had that problem with my '85 Daytona. Turned out the groud wire to the computer was broken and fried it. The tip off was that the computer would give me different codes every time I pulled them. Pull the codes several times over the next few days and see if they are consistent.