You have an exhaust leak. They almost always make a ticking noise. It is coming from the flange connection between the H-pipe and the header. Make sure that the dome on the header is completely seated in the H-pipe. A leak in this area will cause a dramatic loss of torque. You should be gaining a noticable amount of power from this upgrade. The only exhaust smell should be coming out of the tailpipes. Time to get back under there....
