hatch96

i own a 1996 civic hatch dx. I know I have to get a new cat for a header upgrade but i would like to get a carsound cat instead of an ex cat. will there be spots for o2 sensors on the header and cat? if not is it ok to drill into the piping to place the sensores. also do i have to have one sensor before the cat and one after the cat? this is a daily driver so if you guys have any suggestions on what header and cat is best i would appreciate it. also is 2.25 in.pipping or2.5in. pipping better? im new to to board and reading other forums has helped in this area but if you guys could help me out with this I'd really appreciate it. thanks

2000blackgsr

I got a Carsound cat for my HX for $100 and it had a bung for the o2 sensor already. If you get one without o2 bung, take it to an exhaust shop and have them make it for you. One o2 in the header, one in the cat. You might need to buy o2 extenders since they might not fit, or you could DIY w/ shielded wire.

As for the best header, I'd go with DC.

2.25" is fine for a lightly modified car.

Edit - link didn't work

hatch96

thanks for the help.
i know dc's are highly recomended, but does anybody if the Airmass header or the Headman/Chikira header are ok. im looking for mid-range power gains