Tell me everything I need to know about installing a 4-2-1 header.

Vtec95Civic · #1 08-10-2005, 03:59 PM

me and my best friend are taking my 95 civic EX under the knife on Friday (possibly). What do I need to know/be aware of? The header is a DC Sports 4-2-1 two piece. What size wrench(es) do I need, do I need gaskets, are the bolts EVER going to come off (original manifold), how easy is it to strip them, what happens if I do, etc etc.

You might be able to tell this is the first time I've really done anything extensive myself on my car?

Greenblurr93 · #2 08-10-2005, 04:56 PM

lol, havent seen u in a while... anyway, dont be worried, its not that hard. youl need i think a 12mm socket and open ended... the exhaust manifold gasket and the gasket that goes between the two pieces.. youll need 2 new bolts that go between the cat and header (youll need to get these from honda as they are special one use bolts and nuts) and that gasket.... umm i cant think of anything else... it shouldnt take more than a couple hours if you take your time. GOOD LUCK!

superbluecivicsi · #3 08-10-2005, 08:01 PM

13 x 12mm bolts

1 x 22mm bolt

as for the special bolts, you can buy them from honda, or, use a new bolt of the same size and threading and replace the flat areas with washers from your local hardware store. shouldnt be more than $2.

Vtec95Civic · #4 08-10-2005, 08:23 PM

I haven't opened it all up to see what comes with the header,, would these bolts be included?

Do I need a gasket between the two pieces? Someone mentioned to me before that DC has some kind of special way of attaching them so that no gasket is needed.

CivicSpoon · #5 08-10-2005, 09:06 PM

Yeah there is no gasket for where the 2 pieces connect or for where it meets the cat. It comes with 2 rings (seals) for between the 2 pieces and 1 ring for where the header meets the cat. I just watched my friend (kind of helped) put one on an Accord the other day. Check out the flange on the header where it meets the cat, I know the one my friend was doing had a 3-bolt triangle shaped flange on it. He also put a new exhaust on the car as well (Tsudo = shitty), so I can't remember if it came with the bolts to connect it to the cat or not, or if he use the ones from the cat-back.

Vtec95Civic · #6 08-10-2005, 09:35 PM

Hmm I just looked at what it came with. It does indeed have 3 metal rings. It also has 3 bolts that say "W.T 10.9" on them, which if you are correct about the three bolts on the triangle connector, I would guess that those are it? I could have sworn my cat only has a two bolt connection though.

As for the gasket I think I am going to get a new one as well as all new bolts.. makes more sense.

It also came with an O2 harness (I have a new sensor ready to go in already), and 4 ties; where they go I have no idea but I'm gonna guess it's just to tighten everything up?

Now my only fear is stripping a bolt since I don't know how to retap and rethread.

CivicSpoon · #7 08-10-2005, 10:10 PM

The 3 bolts are for connecting the 2 pieces of the header together (unless there are 3 others included). And I'm pretty sure you're right about the 2-bolt connection on the cat, that's why I mentioned it. I'd recommend that you try to test fit the header on first to make sure it's long enough, or short enough, to reach the cat properly. Then buy the 3 bolt flange and have a muffler shop cut the old one off and weld it (or if you or someone you know can do it). That way you won't have to re-cut and re-weld the flange if there is a length problem. I have no clue about the O2 harness or the ties, none came with the header I saw.

Vtec95Civic · #8 08-10-2005, 10:26 PM

Well you said it went on an accord.. so I'm sure the cat to header connection would be the same number of bolts since it's made for the car. I haven't taken everything out of the box because it's in my trunk and I don't want anything to get loose on the chance I damage or lose something. I will test the length before bolting it on.

So how many bolts and what size do I need if I'm getting all new bolts for it? Also, how to I know how much to tighten the bolts?

Vtec95Civic · #9 08-11-2005, 03:42 PM

Mmk..

I have the necessary wrenches (except the O2 one), a new manifold gasket, 13 x 12mm bolts, 1 x 22mm bolt, and the special spring bolts for the cat.

So all I need is the gasket between the header and cat, and the O2 wrench, right?

Also, how do I reset my ECU? I know you disconnect the battery for a few min.. car on/off? Forgive me for seeming stupid I just want to get everything right as this is my only mode of transportation.

Greenblurr93 · #10 08-11-2005, 05:15 PM

car off, disconnect bat for 10 mins.

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