I had my Crawford cats installed a couple of days ago and am very happy with the results. But I noticed Thursday that whenever I go over a moderate bump in the road or a sudden jolt in the pavement, I hear an obvious "clunk" in the rear of my car under the trunk floor. Since I have the Borla exhaust which consists of 3 and a half million pieces I have a feeling that something wasn't tightened enough after the cats install. It sorta sounds like the flanges on the the exhaust are loose and when a big bump in the road occurs the muffler and tips make a dull clunking sound. It is definately in the rear of the car. Is it my exhaust or something else?

 

Give your exhaust a good shaking when it's cool and see if it hits the chassis. Most likely the cats made a pipe or two closer to the body than they were.

 

I'll try that, thanks. If it turns out that's what it is, are there any fixes I need to take care of to prevent anything happening that might damage my exhaust?