What wrong with my car?when in park or nuetral the idles goes up and down non stop and real fast.when i get up to 35 mph the car loses power big time.also sometimes when driving at a steady speed my car****** as if there is no gas or too much gas getting to the engine.a garage tested it for vacuum leaks and said they could find one.i also had a friend clean the throttle body the best he could but there was some places hard to get to.also my exhaust rattles im not sure if that would have something to do with it.was told by a garage it was something electrical like a mass airflow sensor,throttle postion sensor,or air control valve.they scanned it and didnt know which one was causing the problem.car doesn't overheat everything else works fine. 1992 eagle talon non turbo,front wheel drive.