Hey guys, I had my Cattman Y pipe put on last October and when I accelerate hard there is a loud clunking under the car. Now that I have gotten the Greddy catback on my car, The clunking comes everytime I accelerate. I looked under the car and the rubber mount in front of the Cat was broken. I replaced it with a new one and the clunking is gone when I drive regularly but WOT, it is still there. Does anyone else have this? How can I fix this? Is this due to the flex section of the Y pipe?

 

there is a black cross bar just behind the cat that may be hitting. Remove that and see if the sound goes away. If it does, then you can get some spacers and re-install the brace so that it doesn't hit anymore.

 

I know exactly what your problem is. The bracket that holds the y-pipe to the cat is hitting the underside of the car. All you ahve to do to fix this is get under the car, and bend the bracket slightly upward with a screwdriver or another suitable tool. The clanking is because the flex section in aftermarket y-pipes is too short. The stock flex section is a mile long and absorbs the "down and back" motion of the exhuast system under WOT.

See my web site under Power Mods, Cattman Y-Pipe. I have a picture of exactly what you need to do.

http://www.greghome.com