Setzer

I have just cleaned out my cats due to them failing, so now I have 2 holow chambers which seem to make quite a bit of noise at the cats on the exhaust system, I am going to try welding a pipe through the center so it dosnt have to go out to a big empty cat and echo. Any ideas on how to improve the sound quality would be greatly apreciated, besides replacing them.

white90+hibredS4

add a rear exhaust muffler