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?
Exhaust Question for ls swap
- Thread starter ThePope
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UNDR8D
...has a job!
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.
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!
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...
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...
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...
Just found one under for $155 at California Catelytic Converter Good stuff! Unfortunately the CA. legal cat is $288.
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UNDR8D
...has a job!
I mean, what is wrong with the one he has?
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
...has a job!
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.
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.
