1992 Dodge Shadow

Engine Mechanical problem
1992 Dodge Shadow 4 cyl Front Wheel Drive Automatic 146000 miles

My 1992 dodge shadow has been idling high around 2200 rpms. I have taken it in to a mechanic already who just cleaned idle air control sensor. The mechanic also informed me that if it happens again to replace the IAC which I did when it started to idle high again. After replacing the IAC the rpms dropped but went back up after a few miles. I then replaced the Throttle Position Sensor and still the same results. What else could cause it to idle high?
April 29, 2010.

Could be a vacuum leak or its locked-up in the open loop mode and computer throwing fuel at it when not needed or injector leaking/fuel pressure regulator

Apr 30, 2010.