Ok I just bought the truck from a friend of mine and it hasn't been right since I got it. it started out with just a lil hesitation before it would spool up, but within two weeks has turned into a pop almost like a backfire just as its starting to really get spooled up. I replaced the cam position sensor and the map sensor and still no change. thinking my comp box went bad I completely pulled that out and returned the truck to stock. well now the sputter got worse going from sputtering just before spooling up to sputtering and popping all the time. im at a complete loss here, it had codes before I bought it and he had them cleared and none came back, if it was the vp wouldn't it throw a code?