Catalytic Converter / Header????

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!!!!!

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 (http://www.dcsports.com/e-mail.html) sorry i couldnt be of more help

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 (http://www.jdmfan.com/technical/performance/o2sensor_simulator/) to put in it's place. Good luck with it, if you decide to go for it, though. :)

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.

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!

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"

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?

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

www.testpipe.com

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??

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)

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

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?

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.

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. :)

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.

no check engine light so far. the extension is pretty long, maybe about 30 in. long, but as long as its okay, its okay. now i have a clinking noise, i don't know what it can be, for example, when you put it in a higher gear and try to start off, it makes the engine vibrate a little more, so then theres a noise coming from the engine bay, i think its maybe the extension, i ziptied it along the tranny(it was the only way), the plug that connects the o2 to the other connector is maybe vibrating agains the transmission to make that clunking noise. it only happens when the car bogs and the engine is shaking alittle more than usual. has anybody else had this happen with header install? or could it be the header flange vibrating against the cat flange. its not that tight on there, and i can't get the spring bolts any tighter, so may be that too. lots of things, anybody care to share some insight? thanks alot

Hey people,

I was looking online and was wondering what the little mesh part on the pic below is. Is that some sort of catalytic converter or am I just dreaming? I've seen it on others too, like the HP Racing header. Please tell me it's a cat! =) Another question I have is I often see a bulg in many cat-back exhaust systems. What is that bulg? I have it on my greddy cat-back exhaus too.

http://store2.yimg.com/I/streetbeatcustoms_1699_3929723

catalytic converters are for wussys

that's a (more) flexible section of pipe, to help the exhaust system survive all the flexing, shaking, expanding, and contracting that it will go through.

the bulge that you refer to is most likely a resonator, used to change the tone of the exhaust. Another possibility is that you're looking at the muffler...

Originally posted by riight112
Hey people,

I was looking online and was wondering what the little mesh part on the pic below is. Is that some sort of catalytic converter or am I just dreaming? I've seen it on others too, like the HP Racing header. Please tell me it's a cat! =) Another question I have is I often see a bulg in many cat-back exhaust systems. What is that bulg? I have it on my greddy cat-back exhaus too.

http://store2.yimg.com/I/streetbeatcustoms_1699_3929723

It's a resonator can. It's there to both change the sound of your exhaust, and also to help quiet it down a little bit. Without it, it would be noticable louder to a degree. Exhaust systems typically have resonators with them too, I don't see many headers with them though.

for more info on exhaust flex pipes (including pics):

http://www.epiflex.com/newflex.htm

if i keep the cat. converter, are resonators necessary for staying carb legal?? is their only purpose to change sound?

yeah, the only purpose of a resonator (as compared to straight pipe) is to change the sound of the exhaust.

if i go straight pipe, do i need one to stay legal? and what size pipe should i get?

I read a few articles that said that if your car is not producing alot of horse power, removing the cat for a straight pipe will only give u an extra 1-1.5 horse's. It also explained that torque stayed the same or drop just a little. I think the best way is to buy a three way hi-flow cat. 1. smog legal 2. police 3, almost same amount of power. If i'm wrong please someone tell me.

I own a 96 civic with d16y7 and want to get aftermarket haeders. I already have exhaust and cat, but can't find a header for d16y7, if iget one for d16y8-9, will it work????? Thanks

I own a 96 civic with d16y7 and want to get aftermarket haeders. I already have exhaust and cat, but can't find a header for d16y7, if iget one for d16y8-9, will it work????? Thanks

If you already have an EX cat and exhaust system, then the Y8/9 header will bolt right up. ALL '96-'00 D-series motors will bolt up to the same headers, meaning an EX header WILL bolt up to a DX motor. It's just if you plan to keep your DX exhaust, that an EX header won't fit and will cause you to have to alter your exhaust system for it to fit and connect correctly.

hello i also have a d16y7 and i have a full dnx exhaust coming, headers, high flo cat, mid, axle back. what do i need to do to the O2 sensor if anything. and what should i do to pass smog test if any thing. im not in cali or anything im in vt. also could i get the explanation about gas to use again? eg gas to use at smog test and driving gas

With the money saved from buying aftermarket Cat's, it's worth getting a good local muffler shop todo some Art work welding.

I own a 1981 gmc caballero base model. It is a v6 3.8 L. I am having trouble finding headers and a supercharger that will fit this. Does anyone know if they make these for this or if i have to put a different engine in it. If you can give me a websitei can go to or anything it would really help. Thanks.

I'm not familiar with this particular model and year, but one option may be the turbo setup from the Buick Grand National and Buick GNX. I think this same setup was also used in a mid-80's Trans Am. I'm not sure if any bottom end mods would be needed to handle the turbo.

I think the supercharger setup from a modern Buick or Pontiac 3.8L would require too much computer control and top end modifications to accommodate the multi-port fuel injection, etc.

-Rod

Thank you. Its a 229 are they compatable?

229 is a chevy engine rated at 3.8L.. The buick 3.8 is a 331. They are completely different engines If you have a 229, just give up and swap in an LS1 or a 350.

Yuhats what ive got. I wa affriad that id have to do that. Thanks for the help

As long as its emissions ready, taking it on/off it a pain.

So far as altering the catalytic converter setup, I am pretty certain that your car would not comply to CARB standards. Additionally, in CA even if you can find a high flow/performance universal, it must be approved by CARB specifically for your car.

Good luck.

Aftermarket parts do have to be approved by ARB in Ca. They have to have an EO number assigned to them showing they are approved. You can look them up here.
http://www.arb.ca.gov/msprog/aftermkt/aftermkt.htm