New header?
 

I just ordered the Tanabe Medalion Touring exhaust for my car bc my stock one has a leak. Now obviously this exhaust was pricey ($675 shipped kurumamotoring from eBay). So now I have a week or so to decide if I want to buy a Megan header or stick with my stock exhaust manifold? I've heard mixed reviews on headers for civics as they only add 5hp at the very most including exhaust. And I also heard some can really make your nice new exhaust sound really bad and raspy...almost like a crackling sound. A lot of them also start CEL problem. Does anyone else who has an aftermarket header notice these problems? Am I better off just sticking with my exhaust manifold?

If you want to add a little bling then by all means buy the aftermarket. Don't expect much gains from it, the gains are minimal. I would recommend the Megan Racing mani, it's the best bang for the buck. They make great quality headers that you know will fit, not like cheap ebay ones that you hope line up. With an aftermarket exhaust, the header shouldn't affect your exhaust much. It might make it a little bit louder but nothing terrible or much noticeable, and if you do the whole exhaust at once you won't even know. If you want to shell out the $150 for the shiny header (which I totaly would :)) then go for it. And you shouldn't have cel problems, some people may get them if they forget to put their O2 sensor back in, but everything should be fine.

^^ people dont get CELs from "forgetting" to plug their O2 sensors in.....

Every header should have the appropriate holes for an 02 sensor. I think the reason the CEL comes on is because just like y7 exhaust set-ups, the 01-05 Civic Exhaust has the cat converter embedded into the manifold. When you "upgrade", I believe it is removed. Many people do not install a "substitute" cat converter, thus throwing a CEL for something like "Catalyst low effeciency".

See this is what I thought about the cat too, but if you look, the EX header is different from the LX/DX header.

EX

DX/LX


I think that the 2001-2005 EX might not have the catalytic converter embedded into the exhaust manifold, just like it wasn't on the 96-00 EX. If this is the case then you can install the header and retain the stock catalytic converter no problem.


EDIT: Yea, look... the EX has the converter under the car.

EX Exhaust (see how part 4 is the catalytic converter)
EX Manifold

LX/DX Manifold (cat is integrated)

So yea, OP, you can install a header on your car and not get a CEL.

I'm confused. You're saying about the cat and how I should just leave the stock installed, but the exhaust i bought comes with a high flow cat already on it right in the frickin middle. Care to fill me in on what i'm missing? BTW, the part number for my exhaust is Tanabe T70048 if you want to google it and take a look.

You sure you're not talking about the resonator?

Show us a pic of what you are talking about so we are all on the same page.

I think hes referring to a resonator. They may call it a "high flow cat" on ebay though since they love to advertise car parts in ways that are deceiving. I have the Megan Header. Only thing I hate about it is that its a 2 piece. It has blown the midway gasket twice and its a bitch to replace. Im actually thinking of welding it together.

Yes, you're right. Sorry for the confusion...I'm the dumbass.