When i bought my 97 civic ex it already had greddy catback exhaust on it, but where i bought it they are hardcore into the e-check so it still has a resistor and the cat on it. I wanted to get new headers and a high flow cat for it and have the resitor cut off, but what will they do to fill in the space for the resitor just put a piece of straight pipe on it?

resistor for o2 sim or the resistor = o2 sensor?

97 ex = obd2.

hi flo cat or test pipe will require o2 sim. do not cut the o2 sensor, if you do anyways, send it to me ;) weld a new o2 bung for the cat.

when you go for emmissions testing, swap the oem cat back in. plug up the o2 sensor.

i think he means resonator

resonator is just for sound suppression. i had the resonator cut off my greddy evo and put in a straight pipe. $20 at the exhaust shop. the straight pipe will not effect your emissions testing.

well the headers i looked at had a hole for the o2 sensor so if they cut off the resonator will the 02 censor just be moved to the headers and then a new straight pipe be ran to the new cat? How much do you think that would cost?