Searched and tried fixing this many times(auto)

idles revs in park and neutral and now it does it in drive and in reverse and also boggs. when i hit the gas and let off of it. about 1500 to 2000 or more

replaced coolant temp sensor, IAC sensor.. cleaned the hell out of the IAC, checked for leaks...

how much does an iac cost? would a 97 civic iac work or no? cuz i have a friend who might have one.

ne other suggestions would be great..


could i have a air bubble in my coolant. Should i flush and refill that?