i have an h23 in my 4th gen. i did a header awhile ago but i still have the stock cat and no resonator i had it cut out and welded in straight pipe...the piping is decently sized for stock im takin the can i have on their now off and putting on my apexi n1 universal muffler....i had a little trouble with admissions last time i went to have it inspected....should i put my highflow cat on their and go full catbak with the combo of the header..or just putting on the muffler will it make that big of a difference? ...... just curious thanks

 

you must mean emissions, not admissions.

your muffler won't affect the emissions rating, that's what the catalytic converter is for. IMO, get good quality high-flow cat from vibrant, magnaflow or flowmaster. Your stock one might be on it's last legs if you're failing emissions. That or its time for a tune-up and an EGR cleaning.

 

Yeah...a muffler does nothing for emmisions. Get a catalytic converter on there.

 

are u asking if just the n1 muffler will make a power difference?im asking because this thread is titled "power from exhaust." no a muffler will not make a noticable increase in power. i got the apexi1 n1 on my car with the mandrel bent piping, sounds sweet but thats bout it. anything that helps exhaust escape will make hp i guess but none that u will notice.

 

You mean the butt-dyno doesn't register 0.5hp changes?