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Discussion Starter #1
So, I want a new header, but where does the cat go? I don't want to purchase the header and fail my emissions test. please help! :(
 

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So, I want a new header, but where does the cat go? I don't want to purchase the header and fail my emissions test. please help! :(
if it involves moving the converter, it's probably not allowed. They put the converters up close to the manifold for quick lightoff and better emissions, If you move it, it's not going to pass. I'm not sure if anyone makes headers that leave the converter in the factory location
 

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Why would they make headers that wouldnt pass emissions? Ive heard of other street civics passing without stock a header and I was just wondering, does this mean a new header for my everyday driver is out of question? Anyone here replaced the header on their street car? if so, let me know whats the deal, and if theres any way to do it. Thanks
 

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My cat was in the same spot when I switched mine. Every header should leave the cat where it goes, on newer cars, it is either built in or removed. But for your LX, you cat won't move. For your basic D and B series cars, the cat only gets removed from a downpipe, or the exhaust, or a test pipe is put into place.
 

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if the cat is almost on top of the exhaust ports, there is no point in even running a header, the primary tubes couldn't even be long enough to be effective
 

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if the cat is almost on top of the exhaust ports, there is no point in even running a header, the primary tubes couldn't even be long enough to be effective
I agree with this to a point. It really depends on the design of the header from the factory.

Also switching the cats location shouldn't affect its performance as long as its not by the muffler.

He could buy a header and downpipes then a cat from a junkyard or another car . Weld its flanges in for the aftermarket exhaust to bolt into and he's good to go.

The testing places don't care what stuff looks like, they care if there's exhaust leaks or bad emmisions. If your only moving the cat to just after the oil pan it should be close enough. You may want to sand the exhaust system throughly and spray on bbq grill paint. It will keep the heat in and the surface from rusting up horribly.

The more heat you can retain in the exhaust the hotter the cat gets, and the better it will work.
 

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the issue is in places like Cali, you can't move the cat under the car, they won't even let you buy aftermarket cats unless they meet cali standards, that means one designed for undercar use will be illegal there, I have friends there and they tell me universal converters aren't allowed to be sold in the state, and you have to have a certified shop do anything to the cat, even replace it, it's stupid ridiculous there
 

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the issue is in places like Cali, you can't move the cat under the car, they won't even let you buy aftermarket cats unless they meet cali standards, that means one designed for undercar use will be illegal there, I have friends there and they tell me universal converters aren't allowed to be sold in the state, and you have to have a certified shop do anything to the cat, even replace it, it's stupid ridiculous there
So I hear.

If it passes emissions its fine, but even getting them to test a car that is modified seems to be a large obstacle itself. As far as I know they don't do it because its a waste of their time so to speak. Like not testing cars that have engine swaps from older cars.

If someone built the car right and sealed all that heat in it should technically burn cleaner, since more emissions would be cooked off. I know they sell "california cats" or w/e that are supposed to be better than the standard 49 state cats. I don't know if they are actually better or if the company just paid for the certification.

We have some rubber where I work called 16se(self extinguishing) and we make it in the standard 16se bun 54" wide 72" long 2.25 thick, then theres a smaller version of the EXACT same compound. However the 44" wide crap doesnt have the certifications the wide stuff does. simply because the company doesnt want to pay for the cert. This causes people to order the 54" wide shit cause they think its better, when its exactly the same lol.

Makes me wonder about the catalytic converters for sale. I'm not saying they are all the same but I know how shady the industrial biz is.
 

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Discussion Starter #11
Yeah, I get what you guys are saying, but I'm just not sure that I wanna spend 50 bucks on the headers then buy an inline cat, then make the tubing and coat it and seal it all up and everything and find out it dosen't make much difference. I'm on a pretty tight budget, I was hoping there was a way to just swap, but if that is totally out of the question, then I guess I shall switch my efforts to different engine parts.
 

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Haha, yeah, I was literally just looking at eBay cat back header muffler combos. but the one problem I have with them, is I don't want my muffler to be a soda can and make my car sound like a P.O.S. I like how it sounds more.... "Racey", than "Ricey" if you know what I'm saying.
 

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since obviously no one else has noticed, its rather simple. 96-00 the y7 has the cat as part of the header, for the y8 to allow for better breathing it moves the cat to under the engine. when I swapped to the y8 I off course got rid of the cat completely by taking advantage of this. buy the header and cat for a y8, used off of someone that is getting rid of the cat and switching to an aftermarket header and you will see gains without spending money on an aftermarket header.
 

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Haha, yeah, I was literally just looking at eBay cat back header muffler combos. but the one problem I have with them, is I don't want my muffler to be a soda can and make my car sound like a P.O.S. I like how it sounds more.... "Racey", than "Ricey" if you know what I'm saying.
Deleted cat = more noise just so ya know.

If you dont need to pass emissions then you could use the cat as a test pipe, then replace the resonator with an 18" vibrant XQ, and use a apexi WS2 style muffler. That would keep it quiet, however a real apexi is not cheap, 250+ even at a blowout price.

Straight through muffler/resonator with wool packing is what you want.
 

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My eBay header and test pipe/resonator is pretty quite. You just have to match it all with the exhaust for it to not sound ricey. Usually ricey exhaust are the stock piping with a big ass muffler. Just get a 2 1/4 inch all the way through, it won't be ricey.
 

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for a lot less money look at getting a porter muffler, they look like a glass pack but aren't, they have a really nice sound and are still made here, they are quiet at idle but have a good sound when you get on it. I was going to buy one, but I ended up making my own stainless steel muffler
 

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Do you have emissions testing where you live?
Did you get a car that was originally from California?

If you do want to change the exhaust set-up to how Civics with the catalytic converter placed before the mid-pipe, you will want to get a header kit that has pre-installed bungs for the oxygen sensors. One should be at one of the header's collectors and the other one should be before the catalytic converter. If you just have one sensor, then it would be at the collector.
If you buy that "race" header, there is no bung and it will probably cause your ECU to throw errors and it won't pass emissions testing either.
 

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Were you referring to this header Fartbomber?



There are 2 bungs on it. Most eBay ones do, I've seen some that don't though. I know mine had 4, 2 on the header and 2 on the resonator. All where they were supposed to be.
 
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