Brian Hinson

Ok I searched, but didnt find an exact answer. I have a 97 civic CX, and my exhaust manifold is cracked above the O2 sensor causing it to throw the check engine light. I have a stock D15B7 header, and I know it will bolt to the block, but will it bolt up underneath the car?

I think I have to have a piece of pipe welded in, but im not 100% sure. And I know Ive gotta get a new cat underneath the car somewhere. Thanks for the help

E-brake or Handbrake

All D-series headers are interchangeable. You'll need the downpipe to make it fit. If you want to make sure for yourself, go to http://www.hondaautomotiveparts.com and search up both vehicles. They should have the picture for both exhaust systems and that way you could measure it.

E-brake or Handbrake

But with a D15B7 header on the Y7, you will be eliminating the Y7 CAT, which is built-in with the Y7 header. So you'll have to either weld in another O2 bung for the secondary o2 sensor or drive with the CEL on.

murmur9

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Inconclusive &raquo;</TD></TR><TR><TD CLASS="quote">All D-series headers are interchangeable. You'll need the downpipe to make it fit. If you want to make sure for yourself, go to http://www.hondaautomotiveparts.com and search up both vehicles. They should have the picture for both exhaust systems and that way you could measure it.</TD></TR></TABLE>
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Inconclusive &raquo;</TD></TR><TR><TD CLASS="quote">But with a D15B7 header on the Y7, you will be eliminating the Y7 CAT, which is built-in with the Y7 header. So you'll have to either weld in another O2 bung for the secondary o2 sensor or drive with the CEL on.</TD></TR></TABLE>

Brian Hinson

Ok thanks guys...

Is my secondary O2 sensor in my downpipe? If so...

Could I still use my Y7 downpipe, with the B7 upper manifold?

v4lu3s

the y7 has an o2 sensor in the top of th cat and bottom of the cat.

E-brake or Handbrake

Your 2ndary should be visible when looking straight down at your header. It's right after the CAT.

Assuming your B7 header is a two peice, you should be able to use just that. So you'll need to get rid of the Y7 header & downpipe. I'm not sure if you could use the B7 header with the Y7 downpipe...could be a little short.

Brian Hinson

So the B7 is long enough? all I need is an O2 bung?

I couldnt figure out where to look on ur website

E-brake or Handbrake

Here is the Y7 downpipe, exhaust pipe:



and here is the B7 exhaust pipe:



Notice in the B7 diagram, #9 is the downpipe, so use that in conjunction with your Y7 piping.

B7 header, B7 downpipe, Y7 piping all the way thru the muffler. #9 in the B7 diagram will take the place of #3 in the Y7 diagram.

Brian Hinson

Sweet, thanks alot man

E-brake or Handbrake

Try it out and see if everything bolts up, I'm pretty sure it will.

The Y7 pipe is longer than the B7 pipe because the B7 pipe utilizes a CAT right after the downpipe.

But if we compare both complete bolted-up pipes side-by-side, it'll be the same length.

v4lu3s

the header will bolt in just fine, all you need to do is get used to ahvign teh check engione light on all teh time since you wont have a cat unelss you cut your exhasut up.

Brian Hinson

Cool, my CEL is on anyway because of the crack in my current manifold. Would I be able to weld an O2 bung in the B7 pipe an put in another O2 sensor?

Also, would I notice any difference in HP, or would it be any louder without the cat?

E-brake or Handbrake

Just tell the muffler shop to weld the bung so you'll be able to plug in your 2ndary.

As for noticeable HP, probably not. Louder? I'm not sure?

v4lu3s

yes it will be lsightly louder and raspier and your CEL still wont go out, it will show an inefficient catalyst code.

E-brake or Handbrake

You know what, v4lu3s is right.

The CEL won't shut itself off because it will detect a "failing cat". Well, the only cure for that is to replace your whole piping to an ex cat-back.

Brian Hinson

Gah, you would know there would be no cheap solution.

Is my CEL causing a decrease in performance or gas mileage? Just curious...

And would runnin the B7 header without a 2nd O2 sensor cause my car to run poorly? Or even if i did run the secondary one, and the CEL comes on, Would it change anything?

If it runs the same I might just do it anyway to get rid of the sound of that exhaust leak.

E-brake or Handbrake

The secondary is to tell you if your CAT is good/failing/ or dead.

Running without the secondary would probably decrease your performance--the ECU may make your car run in LIMP mode until you fix your "failing" CAT.

Don't take my word for it though, have someone confirm my statement first because I'm not 100% sure.

Redline96LX

in conclusion:
**** the y7 exhaust. i know, i got it. and i cant just get headers, gotta like replace half the ****** exhaust system.

E-brake or Handbrake

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Redline96LX &raquo;</TD></TR><TR><TD CLASS="quote">in conclusion:
**** the y7 exhaust. i know, i got it. and i cant just get headers, gotta like replace half the ****** exhaust system.</TD></TR></TABLE>

You show so much animosity towards the Y7 Calm down my friend

Brian Hinson

Haha well thanks for all the help anyway guys

I guess im just gonna have to save some pennies untill I can afford to buy a whole EX exhaust somewhere

Brian Hinson

Just one more thing, why is it so common to see the Y7 exhaust manifold cracked right above the O2 sensor? Is this a flaw or something with the design?
This is probably the wierdest exhaust Ive seen on a Honda

Brian Hinson

Ok, the B7 header does fit just for those who are wondering. Its the same length as the Y7. I bolt it on today.