just installed a used dc 4-1 header, and new ws2 exhaust on my 99 si. The header had a tapered gasket that i just reused, and it went right up to the stock cat. love the setup and don't want a test pipe ( for earth) so my questions: Does a cat with 180,000 miles still work correctly, and is it worth keeping on or should i just get a highflow carsound?

 

bump. anyone?

 

if u dont get shitty mpg and cat converter does not rattle inside. then u are good

 

are you passing emissions it so i would bet that it is just fine

 

my mpg is between 25-28, thats about normal right? passed emissions about 8 months ago. Don't fix it if it ain't broke huh? 1 more question, do you think its adversely affecting exhaust flow? forming a "bottleneck" or "hourglass" being paired with the header and cat back?

thanks for your input guys