hey guys i was just wondering if i should go get a header first or exhaust system... and is there any compatibility issues with different header and exhaust... I was also wondering which one gives you more of a performance increase?

 

personally, I'd go with a header first. If you have a stock exhaust manifold and an aftermarket exhaust, the exhaust gases are still being compressed in the exhaust manifold, so the cat-back really doesn't accomplish much. As far as I know, any header will fit up to any exhaust. The only think you might have to worry about is the catalytic converter. On most civics, the ex and si models have a seperate cat, whereas the dx/lx/etc models have the cat built into the exhaust manifold. If you have a dx/lx/whatever, you'll either need to find an aftermarket header with a cat built into it, get an ex/si header and have a test-pipe welded to the exhaust system (and fail emission testing), or convert your entire exhaust to ex/si specs (get an ex/si header, catalytic converter, and cat-back exhaust). And it's pretty much agreed upon that a header/exhaust will each gain 5-ish horses (well, 3-5 realistically).

 

Thanks that was very informative. So i should be able to pass emmision test if i get an megan racing header and exhaust without touching the catalytic converter right? BTW I have an 04 ex sedan...

 

yea you will be alright, if you get a cat back and remove the cat and install a bung in the header you will also pass emissions.

 

lol. no.... just no....

 

+1... MR's headers are not emissions-legal. What does this mean? It means that it's almost garanteed that you will fail emissions testing. And you need a catalytic converter to pass emissions. That's the entire point behind a cat: to decrease emissions.

To pass emissions, you need an emissions-legal header and an emissions-legal catalytic converter, hence the term "emissions legal".

 

uhh buddy...the MR header for out 7th gens WILL pass emissions...it doesnt delete the header


kthnxbye

 

my bad... anyways, you'll still need a cat to pass emissions.