you sound like you have a vacuum leak of some kind. look into the throttle body, you should see 2 holes for the idle air one on the bottom and one on the top. they are kinda to the left. put you finger over the bottom port. it should stop idling abnormally. if this is what happens it is a relatively easy fix. try this and shoot me a pm. or just hit me on aol im. i have run into this problem before.