cubism

catco hi-flow cat and apexi N1 cannister with custom 2.5" piping all the way through on a 97 hatch with Comptech 4-2-1 headers & AEM coldair intake?

and how do i know if i need an o2 sensor bung? it's a 97 civic cx.

or ?

slowturbocx

if theres not one on the header you will need to put one on the exhaust

slowturbocx

i doubt there will be but they are cheap to buy (o2 bung)

sockvtec

MikeD718

wont he also need a second in the cat? i had one on my 98 ex

Deemeetree

Well, the head should come with the O2 sensor bung already welded in. Usually, they try to keep everything cat compliant.

As far as the custom piping, I doubt there was an O2 bung welded before the cat. Buy a bung for a couple bucks, have it welded in for a couple bucks, off you go.

Since the ECU is OBD2, there should be 2 O2 sensors.

Someone can chime in and concur of the 1996+ OBD2 Civics are 2 O2 sensored.

shifty35

This setup probably won't work. The Hatch's all have the cat integrated into the manifold, so there is no cat underneath. Because of this, the exhaust piping is longer to meet up with the manifold. So, if you put the headers on, the cat will not fit in there. You will need to run an O2 simulator and your car will no longer be street legal, and likely throw codes w/o the simulator.

Ghetto Civic HX

^^^^^
That'd be true about the header if he were getting an off the shelf catback. But he said he was getting a custom exhaust made.

About the o2 sensors. I'm pretty sure your car has two o2's. The header should have a bung for your primary o2. You could leave the second one hanging, but like shifty35 said, you'll throw a CEL code. An o2 sim will keep the light off, but it will stay in your computer's memory. Come inspection it will show up.

If I were you, I would have the muffler shop put on a cat and put an o2 bung after it.

Lee_Delso

On my 97 Del Sol there are two O2 sensors, one in the manifold and one in the cat.

dantastic

what car is the header for? if its for a GSR, then it'll be missing a bung. if not, it should have a bung in it.

is the cat obd2 compliant? then it should already have a bung in it. if not, you need a bung put in right after the cat.

haha. i said bung.

slowturbocx

no he could get an universal high flow cat and put his o2 sensors in with out a problem it is obd2 so there are 2 i forgot