the last time I had the codes checked at Autozone everything referred back to the camshaft. I know a little bit about cars but puzzled about the camshaft. Could this be just a sensor if not can the camshaft be replaced and recently the car is running a bit more rougher on a couple occasions on start up it rev's up and I have to hit the gas to get it to rev down. Could this be related to whatever problem I'm having with the camshaft. Also has anyone had one changed at the mechanic and about how much was it. Thanks 