what does it sound like when the cats go out ?

[Speedy_Gonzales]

My car has a funny sound to the exaust. Sounds like an exaust leak. Not had the chance to look under it and see. The cut-out is closed tight so it cant be it. It started this not long after I did the throttle body by-pass but that would have nothing to do with it. No codes and performance is the same. What does i sound like when the cats start to go ?

[Boomer Sooner]

they rattle like crazy(the cats). on my old 99 v6 camaro, i was experiencing a rattling coming from what sounded like under my passenger side floor. took it too an exhaust shop and they said my cat was bad. i just had the cut it off and put in a straight pipe. i didnt give them time to go bad on my Z, i just had them cut off and had straight pipes put in their place.

[LS2Tuner]

Just wait until it's cooled off (exhaust) and lay on the ground and give the cat a good whack with the side of your hand and it will rattle and sound loose. Don't wait because if it's beginning to rattle or come loose it can break apart and start lodging pieces in the piping and even plug up the muffler. Shit I have had customers cars where we ended up having to replace the whole exhaust due to 10-15 pieces of shit lodged in the pipe and muffler. . . . . . . . . .

[Speedy_Gonzales]

Just wait until it's cooled off (exhaust) and lay on the ground and give the cat a good whack with the side of your hand and it will rattle and sound loose. Don't wait because if it's beginning to rattle or come loose it can break apart and start lodging pieces in the piping and even plug up the muffler. Shit I have had customers cars where we ended up having to replace the whole exhaust due to 10-15 pieces of shit lodged in the pipe and muffler. . . . . . . . . .

whats the best way to punch out the cats ? will it effect mpg ? will it put out dangerous fumes ?

[Speedy_Gonzales]

my problem was I didnt have my cut-out closed tight enough