Just wondering how long these main cats are supposed to last. I just hit 100k miles and the main cat is the only original piece of the exhaust still being used. How will you be able to tell if they are beginning to get clogged?? Any info. is appreciated.

 

You will boost significantly less, and your downpipe or precat will glow cherry red.

 

does it make any sounds? like a ticking sound? I'm close to 100k too.

 

Well, there's an annoying squeaking sound....hanger perhaps...or I looked underneath and saw a piece of heat shielding on the pipe about 3 inches long that had come unwelded and can slide back and forth. Sounds identical to a belt squealing...but it's not. It's coming from underneath my car. SO, that heat shield is what may be making the noise. Other than that...no ticking noise.

 

you guys are lucky to hear this.

my 7 has 106k miles and i just took out the stock main cat to replace with n-tech hi-flow cat. (my 7 had been a bone-stock until 98k)

main reasons i got the new cat are...
- takes longer to boost up to 10psi
- slightly lower boost (8 psi)
- couldnt even pass a pre-smog test.

now i passed CA smog test with coldair intake, DP, n-tech hi-flow cat, and greddy PE. of course i passed with flying colors.

oh, BTW, i could see small chunks of honeycomb comming out of the old main cat when i shook it. im pretty sure it was extra crispy. :p

 

Boy am I glad to hear that. I'm still w/ original cat too.