Catalytic Converter / Header????

[riight112]

I am planning to get a header for my 99 civic hatchback but had a question about my catalytic converter. Unlike most other cars, my catalytic converter is located inside my engine bay, between the location where the exhaust gases flow out of the four pipes and the down-pipe that connects to my exhaust. If I get a header, do I lose my catalytic converter? Can I get a 2-piece and put my stock catalytic converter in between? Do I need to relocate any of my oxygen sensors? Any suggestions? Anyone do this before? Anyone know of a straight bolt-on replacement of some sort? I have a stock engine (d16y7) with a AEM CAI and a greddy SP cat-back. HELP PLEASE!!!!!

[strodda]

i honestly dont know, but my guess is better than nothing. i would assume that if a direct fit replacement is available, you should be fine. just email dc and find out . DCsports sorry i couldnt be of more help

[SilverY2KCivic]

Unfortunately in our D16Y7 cars, you WILL lose the catalytic if you replace the stock headers with aftermarket ones. Big drawback too, because it'll require you to relocate the 2nd (bottom) 02 sensor, by legnthening the wire to it, which will cause increased resistance to the sensor, causing it to read incorrectly. Point being, that method can't be done, you'll have to get an 02 dummy sensor to put in it's place. Good luck with it, if you decide to go for it, though.

[Tominos]

i just bought dc headers 4-1 for my civic ex. they relocated the o2 to the bottom of the header near the end, so r u saying this will cause it to read incorrectly? b/c it comes with a plug to lengthen the 02 wire.

[riight112]

What happens if I lose my catalytic converter? Or can I live without it? Or do I need to buy an aftermarket one and put it on the bottom? Would my car not be CARB legal anymore then? What's the difference between a one piece and two piece besides the obvious? Does one offer an advantage over another? Thanks for the info SilverY2KCivic!

[strodda]

in california it wouldnt be carb legal... having no cat is the same as having a straight pipe, which isnt legal. although no cat would give a little extra power, and depending on how much sound it adds, you may never get caught. but i personally wouldnt take the chance.

a 1piece might be a little lighter since you lose the middle flange, and supposedly the air moves more smoothly through the downpipe(so websites tell me). they just say 2piece sets are for "ease of installation"

[riight112]

Could I get a header and then add an aftermarket catalytic converter and bolt them both on? Is there anyway to save the second oxygen sensor? Or do i need to get a simulator for that sensor? Is Catco catalytic converters good? Any other good brands out there?

[thewoahna]

I had a Catco and it worked good for me till I upgraded to a test pipe....

www.testpipe.com

[strodda]

well imo, going from a catco highflow converter to a piece of metal is kinda downgrading, but it would help performance...

anyways, how many miles are on the catco, and would you sell it??

[riight112]

Would I be able to put a an aftermarket header on and put a catco catalytic converter after it on my car? (civic 99 dx hatchback w/ greddy sp cat-back exhaust, d16y7)

[Tominos]

yes, i think you can, get headers for ex, then get ex cat or similar and then get ex exhaust system.

[riight112]

Is it possible to get a header and a catalytic converter and still be able to keep my greddy exhaust? Any good brands on the header and the catalytic converter?

[Tominos]

for headers, i went with dc sports 4-1, power up top. the thing is, when you want more power, as in racing, you're going to be driving at high rpms anyway, so why not get the one that makes most power at 5000 rpm plust. as for catalytic converter, there is no such thing as a race cat. if it doesn't have the stuff inside the cat, then its useless, might as well get a test pipe, much cheaper. my friend bought a so called race cat for his integ. and i looked at it, looks like a resonator, with an o2 bung welded on it. as for your exhaust, you would have to cut it probably, because on the ex, the cat is at the bottom of the car, not in the engine bay like the dx. sits right after the headers, you will see what im talking about once you get your headers.

[SilverY2KCivic]

Originally posted by riight112
Is it possible to get a header and a catalytic converter and still be able to keep my greddy exhaust? Any good brands on the header and the catalytic converter?

Definitely. You can get EX headers, and then get an aftermarket hi-pro or EX style cat, and hook it up after the headers, and then hook your exhaust up to it. If the exhaust isn't for an EX, or the cat is shorter or whatever the case may be, you may have to have your exhaust piping lengthened, or shortened.

Tominos I've heard from tech people that lengthening the wire will add resistenace to it, and that's what the signal to the sensor relys off of. Read up about it in that link I posted up above about that. But if you say it comes with a wire lengthener, then hook it up and see if it causes your check engine light to come on. If it doesn't you're good to go, if it does, then the resistance thing holds true. Try it out and let us know.

[95cvccvx]

I have the same set up in my ride. Change the manifold and bought a aftermarket cat. Any other changes to your car make sure you bring it back to stock before the smog test. The changes you planing on doing your car will become more rich and you want your car to run leaner to pass smog. Stay with 87 octane, higher will burn out your cat unuse fuel. Plus run a hotter thermostat then replace back to the cooler one 180.