I started my car today and noticed it had a rough idle. It was idling ~ 600-800 RPM. All I have is a K&N filter (for now) and was wondering what the problem could be. I was told that i might have a COP gone bad and not firing. It idles so rough the car shakes and feels like it could die. Surely this is not normal for a stock engine. Oh yeah, my car is only 3 weeks old w/40k miles - 01GT