ekhatch

ok i got a set of vibrant 4-2-1 headers for my 2000 civic hatch, what i wanted to know is, if i remove my old headers (has a cat built in) and replace it with the vibrant headers, will i need to do any modifying? i still have stock exaust piping, will the headers just bolt right on and will the check engine light come on without the cat? would i need a high flow cat and would that work with my stock exaust piping? let me know thanks

BoostedEh2

its obd2 so your going to need two o2 bungs(one in cat one in header) hopefully your header has a bung already welded in and your going to need a odb2 cat so you can plug your secondary o2 sensor.

ekhatch

im lost haha, i know my car has two o2 sensors, 1 i know of is right on the header, my new headers have the o2 sensor hole for the header o2, but where is the other o2 sensor connected to? let me know thanks

BoostedEh2

with obd2 you have an o2 in the cat...so since your taking out the stock header/cat...your going to need another obd2 cat to put in...get it?

ekhatch

ohh ok i get it ya yah, but where would i have 2 re-locate it? sine the o2 sensor wire isnt that long, what would i need to do?

shooter78

You'll have to extend the 02 sensor...you can buy extension kits or do soldering so it will reach the cat which you'll have to relocate under the car instead of its stock location...

Are you doing this yourself or is a shop doing it for you? If your taking it to a shop then you don't really have to worry they'll know what to do...but if you run your set up without a cat you'll get a CEL and you won't pass emissions...

ekhatch

ok so heres what ima do, put the headers on, get a high flow cat plug in the o2 sensor to the headers extend the other o2 sensor and plug into the high flow cat located under the car, but heres what i wanna know, will all this work with my stock piping? do i just get a reducer meaning 1 end of the small pipe is 2.5 and the other end is oem size so the cat can fit on the oem piping or? what should i do? i dont wanna have 2 get all new piping just to put on headers and a cat

BoostedEh2

you wont just get a hiflow cat that will fit your stock collector flange

shooter78

I think you should say bye-bye to your entire stock exhaust system. Get bolt on's intended for an ex of the same year. The key is that you would have to replace everything.

I'm doing the same thing with my 05 coupe. My header has the cat in it so I bought an aftermarket header for an ex, along with a highflow cat for an ex, and a full cat back. I have everything in my living room finally and am having it all put in on monday morning.

You already have the vibrant header which I'm sure is meant for an ex because they don't make a header for your engine. Add a highflow cat from magnaflow and a cat back exhaust and you'll be good to go...you might need some piping from the header to the cat...not too sure about this though...take all your stuff to a reputable shop and they'll make it fit under your car in an hour or two.

Anways that's what I would do...you've already invested in the header you may as well finish it off.