I sold my 03 Cobra to a friend and I am keeping the car for him while he is in Iraq. He swapped out the high flow cats for an off road pipe and it is way too loud with the Stinger exhaust. I am getting ready to take it to HPP this weekend to add a KB and a lot of other stuff. We are trying to figure out what to do to keep the flow right and quiet it down some. He took off the high flow cats because over time they blew out. What do you guys think? This car has an HPP stroker with stock headers. I suggested putting long tube headers and maybe a different cat back.