We just had a new Y-pipe and converter put on the truck. It came as a kit. Before we put the new parts on, the pipes and converter were terrible. With a new exhaust, and everything tight, its running like it has a racing cam in it. Yiu can hear and see the motor shaking, and when you give it gas in Park, its not bad, but when you go to Drive and give it gas, it hesitates, shakes, etc..like its starved for fuel, or being choked out. Its a 5.8 Liter, "351" block, and it just started to do this. It allreadu hurt is for $600 for the Y-pipe and converter, what now??