just wanted to give my 2cents on what the sr hi-flow cat with the stock exhaust sounds like....and its good. Not ricey at all, not loud at all. gives a nice low growl which you can hear fron inside but not loud enough at all to drown out a conversation and it sounds almost normal while cruising at a constant speed. I absolutely hate hearing a lame civic with a massive tip go by and just had to say the cat along is not loud at all, just gives a nice low growl.

if this is said somewhere else my bad but in my search for a cat i didnt see anyone talking about just the cat with the stock muffler

as far as any hp gains...maybe a very little?. Sounds faster and maybe a slight difference but i hadnt driven it for 3 weeks(body shop) and installed the cat before really driving it again andwhenever i take a break it always seems faster. Well hope this helps someone.... in a way. Money well spent in my mind

and yeah i see i wrote car instead of cat in the tittle.... leave me alone...