l have a 96 dodge intrepid.Recently its been idling high.When its in park the RPMs shoot up to 2000 RPM and stays there and when im driving it the RPMS are at the lowest around 1000 RPM.Also when l brake to a stop, it jerks forward just before a stop.Just yesterday the check engine light turned on and so l took it in.The mech gave me a print out.It said something about ''idle speed not being reached''It also said the the IAC could be the problem or a vacuum leak. I am wondering with these symptoms is the IAC the most probable problem or anything else.Also where is it?

The Air Idle Control motor is attached to the throttle body, & can go bad, but l have seen many more vacuum leaks caused by intake manifolds & plenum (upper intake chamber) leaking. Try this, while idling the engine spray small amounts of starting fluid at the area around the intake to head surface, plenum to intake & around the throttle body to intake plenum, any increase in engine speed indicates a leak. A fully functioning scanner/ diagnostic tool will be able to actuate the AIS motor & determine if it is working.