i am so sorry but i am too lazy to search.

i have a 2000 civic sir, which is the same as the american Si which has the b16a2 motor and im just wondering, will aftermarket headers fit a stock catalytic converter?

thanks

 

Wow, I must say I do admire your honesty. And for that I will SF.

There are a $#!T-Ton of aftermarket headers availible for that application. Most if not all will require exhaust modifications from your local muffler shop.
And all of them will do jack $#!T unless tuned with some sort of engine management.