I have a 2001 Ponitac Grand Am Gt. Occassionally my car will drive itself. It used to be when I was on a long trip (and mostly when it rained) and the engine was hot that it would accelerate without putting my foot on the gas. I drove from one end of town to the other without touching the gas. I can stop the car when I put my foot on the brake and the problem would correct itself when I turned the car off. It also revs high when in park when it does this. But, the last time it did it I hadn't been driving the car on a long trip nor was it raining. I have asked a few mechanics and all are stumped. I have just recently changed the intake mainfold gasget which had been leaking and it did not correct it either. My service engine light is on and the code is the egr valve. Would this cause this problem?