Ok, so i bought this 2003 Cavalier with 30,000 miles on it. I have had it for about a month now and some weird stuff goes on while I am driving it. It isn't an everytime thing, it happens at weird times and locations. I will be drving down the interestate and after about 30 min or so if I get off the interstate and coast to the stop light, my engine will stay revving at 2-2.5k rpm. Then other times if I am driving for a little while the engine will shut off, like stalling while I have the cluth in. WTF? I took it to the dealer and they found nothing wrong, obviously there is something wrong. Any ideas?

Make sure nothing is touching your throttle cable. Also, check the ground wires, make sure they are solid connections, otherwise I really don't know what to say.

So I got the problem fixed. Apparently there was a problem with some of the 2003-2004 Cavalier's PCM. The PCM would let the idle drop to below 500rpm causing the car to stall. This is problem that was fixed in about 30 min by reprograming the engine management system of the PCM. If it wasn't under warrenty the cost would have been $21. No problems any more.