my 96 neon Has a very strange problem, the idle sometimes (Not Always) sounds like some one is sitting there reving it. It will rev up to just below 2,000 rpm than stay there some times for a second or two or it will stay there for a long time. it will also drop very low like 500 rpm and sound like it's going to stall or run out of feul. and like i said sounds like some ones in the car reving it from 500 rpm to 2000 Rpm. I checked the repair mannuel and there are only a few things it says and I checked most of them.

any ideas?

 

NOT SURE IF YOU GOT YOUR ANSWER BUT IF DO LET ME KNOW I'M HAVING THE SAME PROBLEM BUT I UPGRADED MY THROTTLE ON MY CAR WITH AN AUTO THROTTLE I'M GONNA CHANGE THE TPS ON IT AND CHECKING AGAIN FOR CODES I LET YOU KNOW WHAT HAPPEN

 

Most likely cause is a sticky IAC valve. Carb cleaner tneds to fix it. Remove the TB, grab soem rags and q-tips, and get busy...

Best of luck!