ThePope

Hi everyone. This last weekend I completed a 98 ls swap into my 98 civic DX. I'm very happy with the results but I now have to start looking into an exhaust system. Currently I'm using the head pipe from a 99 civic ex to connect to my stock dx exhaust but I plan to reconnect the ls head pipe when I get a new cat and exhaust. I'm considering a custom exhaust set up from a muffler shop but some of the quotes I've gotten have been as high as $1000 for the complete cat and exhaust system. Is that an outrageous price? What price should I expect for a nice exhaust system from a muffler shop and are there other exhaust options available for a civic ls swap?

UNDR8D

For my LS swap, I bought a header and test pipe, and made my own exhaust from there back. It wasn't hard but I don't recommend it. The exhaust for your car will just need to be lengthened about 2.5 inches in order to meet up with the LS cat. So buy a performance cat back or whatever you want, that is made for the DX. Because the exit locations are almost identical between the D and B series, you can just add in a small section of pipe right after the flange that bolts to the cat. This should lengthen it enough to fit the LS and your car. That is the easiest and most economical option.

BrutalB83

$1,000 for a muffler shop exhaust? That's absolutely ridiculous, don't pay that. They're probably figuring in the cost of a completely new catalytic converter, which shouldn't really be necessary...

ThePope

Yeah that was for a new cat, priced alone at $495. Just got back from another shop that wanted to charge about $900. The guy at the shop said it was cheaper for them to order a greddy cat back for $400+ and customize it to mate with the catalytic converter than it was for them to bend their own pipes and make a custom exhaust. UNDR8D I think you've got the right idea but I'm still going to shop around a little while. About 5 years ago I got a custom borla cat back exhaust for a celica and with parts and labor it was only $160. Granted it did not include a cat but it just seems the cost of muffler customizing has gone through the roof!

BrutalB83

You can buy a Magnaflow cat converter that will flow better than stock and will be far cheaper than a stock replacement. Alternatively, if you live someplace that doesn't do emissions testing you can just delete the cat altogether and run a test pipe in it's place.

Honestly though, Honda cats flow pretty decently from the factory. Unless yours is clogged or otherwise defective, or you simply wanting the pipe size to be consistent all the way back to the muffler, you don't really need to replace it...

ThePope

I live in CA so I definitely need a cat, at least initially to smog it. Would a bolt on after market exhaust made for a 99-00 civic si fit on my 4dr civic with a little extension on the cat? Would the bends in an si exhaust be the same as the dx from the cat back?

BrutalB83

It might fit yeah, but to be safe I'd probably just buy the correct one for your car. Is there some reason why you don't want to do that?

ThePope

Actually, now that I think about it, you're right. Sorry, i was making things too complicated for myself. I'll get an after market exhaust and have it adjusted to fit with the cat. Thanks guys!

BrutalB83

That will probably be the best option for you. Shop around a bit if there's a certain size of piping that you want. Or check out Welcome to Kteller.com if you want a custom pipe size. That's where I got my exhaust from. It wasn't exactly cheap (it was about $500) but definitely better than a grand...

Justin66

dang i got a decent cat for $150

ThePope

Just found one under for $155 at California Catelytic Converter Good stuff! Unfortunately the CA. legal cat is $288.

UNDR8D

Why do you need a cat?

BrutalB83

He lives in Cali, so he'll need one for smog testing:

Justin66

Ya is pretty strict over here for e-testing. My car was no where near passing for NO, lucky since my car is swapped i was allowed to test it as a "hotrod" and my limits were far higher so it was no problem.

UNDR8D

I mean, what is wrong with the one he has?

BrutalB83

Ah, yeah, good question. I pointed that out earlier actually but I think it got overlooked...

There's really no reason that it needs to be replaced since Honda cats flow pretty well from the factory. The only reason to do so is if the cat is a lot smaller than your downpipe and/or exhaust pipe (creating a bottleneck), or if it's clogged or otherwise defective...

UNDR8D

Exactly. And on a stock LS, he will not be making near enough power for it to matter. If you don't need a new cat then it is an unnecessary expense.

ThePope

The cat for the old DX motor is located on the header were as the cat for the LS motor is located right after the head-pipe. I don't believe the old cat will fit. It will definitely not fit as a bolt on piece. What I've since done is ordered a cat for the integra LS ($330, expensive but CA smog legal) and the apexi ws2 exhaust for the civic ex/si. The Civic Ex and SI both have the cat located after the head-pipe just like the LS so it should bolt up just fine, although the exhaust pipe that connects to the cat may need to be adjusted in length by a muffler/ metal shop. As far as I can tell the bends after the cat are the same on all 92-00 civic coups and sedans so from the cat back the exhaust should fit right in. This way I can take the cat off later and insert a test pipe for more flow without having to deal with welds from a muffler shop.

BrutalB83

Sounds like a good plan to me!

Yeah I had forgotten that some of the Civic models have their cats mounted up high like that...

ThePope

Put the exhaust and cat on this evening. It fit like a glove! Thanks for the support gentlemen.

bfraley

Great that it turned out well for you. I'm installing a B18 into a 97 DX hatch. I'm using the stock B18 exhaust manifold/downpipe. I picked up a Magnaflow B18 cat and a magnaflow cat back system for a coupe. I'm hoping it's a direct fit for the hatch. Anyone have experience with this exhaust issue? Not sure if I should start another thread or not. Thanks

BrutalB83

Awesome man! Glad it worked out for you!

Well, yeah you probably should start your own thread, but since you're here...

I don't have any experience with that particular combination, but I'm thinking that it should be close enough to work, or close enough that an exhaust shop could make it work rather easily...

bfraley

Thanks for the feedback! Have a good one.

UNDR8D

Ya I forgot too. I just remember that the cat on my old D15 was on the bottom where the LS cat is.