I have a 95 A4 Z28 (stock) and my cat is rattling. I have done searches on the site and found out that it is probably either the heat shield or the stuff inside of the cat. Anyway, I wanted to know your guy's opinion on if i just took the cat off. Does it sound nice, or is it an annoying sound? What kind of gains would I see? Any help would be appreciated. Oh and I dont have to worry about emission. Thanks

 

I had a rattling cat and it was annoying. The sound a loose heatshield makes is different soound than loose material in the cat. The loose cat sounds like rocks in a tin can, the loose heatshield as a vibrating lower tone if you know what I mean. Eventually you'll blow the loose stuff out of your cat but it would still need replacing.

I live in Canada, every 2 years we have to pass emissions. When my cat started to rattle I failed emissions until I replaced it.

I woundn't recommend running w/o cats. The computer relies on O2 sensor feedback from the cats for the car to allow the car to run well. Also the cats provide some needed back pressure. I would also image the car wouldn't sound too hot either. If you have the $$$ get a high-flow Random Tech cat replacement. I have and love them.

 

i had that....had to rip out the guts. no biggie and deeper sound

 

sell it and get an ls1..











haha just kiddin.. get the random tech cat replacement.. ill even install it for ya

 

thanks for the help guys, i think i might get a high flow cat, but im not for sure yet. anymore opinions?