What will a tune do to my warranty? I don't want to screw that up. I did find another potential problem this being a slight exhaust leak at the ball flange right behind the cat, the ball clamp is as tight as it can go metal to metal completely tight. I think the ball flange on the head pipe that came with the cat back system was not formed properly and I'm wondering if under the conditions that popping happens air/oxygen is getting into the exhaust pipe and igniting sunburned fuel.