I was looking at getting a test pipe for my civic, and im pretty sure i need a 2 1/4 inch pipe, right? And also, it says i can get them with or without an O2 sensor bung... im think my car has an O2 sensor hooked up to the cat, so i guess i better get the one with the O2 bung on it to keep my check engine light from coming on?

yeah you need a 2.25" you can also use a 2.5" if you want and the part about not making you CEL come on won't happen it will more than likely come on with a test pipe. if the light does come on then you have to get a o2 sensor simulator.

OBX makes test pipes with an extra o2 bung.

uh huh huh huh uh huh huh huh

you said bung

uh huh huh huh

So i do get the one with an O2 sensor bung?

he said bung to hehehe

Your car should be OBD1 and there shouldn't be an o2 sensor in your cat.

you won't pass inspection running a test pipe

That's why you keep your cat in your closet then when inspection/emission time come you take about 30 min to bolt it back in.

don't get rid of your o2 sensor. i've heard that if you do, the computer doesn't read right and can cause problems down the road???