Srt2Stang725

Whats up everyone. I am running a pypes offroad x pipe on my 07 GT. Since day one of installation i have had what sounded like an exhaust leak. Being that ive never had a v8 car before i was hoping that it was just the sound of the catless xpipe.....but the other day it starting making me mad so i got underneath the car and used a telescoping mirror to see that the top of the driver side exhaust manifold to x pipe connection is leaking. So to make a long story short no matter what i do to this xpipe; no matter how i torque it down, even counting the number of rotations of each nut it still leaks. Does anyone have this issue? Any advice for me? Thanks