Jomyke242

Hey all - any help appreciated.
Just picked up a 2000 Civic with a D16Y7.
Exhaust manifold opened up on the way home (grumble grumble)
Plan for this car is to get best MPG while stacking 25k/year for a couple years.
So we are trying to run cheap/efficient here.

Looked at stainless 4-2-1 which is cheap, but I have the cat in the manifold - or right up close to the manifold - so this option either deletes the cat or I need to move it under the car.

don't mind having to move O2 sensors (extend wires, if needed).

Don't want it to be loud.

Previous owner just replaced from Mid-pipe back.
Interestingly the Midpipe is just -u-clamped to the tail. Meaning, I see on the 4-2-1 with a test pipe, that the connection to the cat-back (tail) is expected to be a bolt-up. But here they just slipped pipe over the midpipe and clamped it with a round pipe clamp.
Is this going to be a problem for me? Is this a shitty job done or what?

Recommendations?

My thoughts
1) Junk yard and pull a manifold. Cross fingers that this manifold holds up and that the existing downpipe and midpipe survive the swap (they are pretty rusted looking - probably OE). Concern here - can I split the existing cat off or do I just take my chance that the cat I get isn't **** already?

2) Try the stainless 4-2-1 route, and have to (HELP here) figure out how to attach the test pipe (cat) to a straight pipe that is there...??? (cut the cat/test pipe bolt flange off and clamp?)

3) I see Dorman OE replacements are ~$350 as they have the cat with them. I'd love to stay under that for cost, but willing to listen to reasons to go this way

4)Because of the (shitty?) clamped midpipe deal - just replace the exhaust front to back with something that will be cheaper? (doubt that exists)

5) I saw something about an EX swap - puts the cat under the car and could work if I can figure out how to connect to the cat-back I have (which, again, is new)???


Much appreciated! I tried to do my homework first, but can't quite connect the dots to an answer that works for me!

redm3turbo

1)your going to be hard pressed to find a non cracked mani from a junker....Ive never seen an uncracked stocker...its a real common problem. If your car has under 140k miles, you can try to get it repaired at the dealer as part of a tsb.... Ive heard of some getting, and most not. Depends on if your car was dealer serviced, or how nice the service dept you have near you.

2) assuming you got a stock lx exhaust, if you put on a header, your going to either need, a complete ex exhaust to bolt up, or know a welder that wants to help, or your going to pay. A ex exhaust like you know moves the cat under the car ( and makes it alot cheaper) but it also isn't going to bolt up to the lx piping (stock for stock)

3) I paid 250 for my oem replacement mani/cat. I did however sell my oem cat conv for 80 bucks. Last I check they were paying 40/ for a cat...however, it could be more or less now....you'd have to check. scrapers will pay for them, even come pick them up

4)if you can access a pipe bender..you can get a cat back made for around $20 in supplies. Pipe isn't much, however I only know of 1 person that has access to a pipe bender, and he works at a muffler shop. If you want to purchase it already bent...your looking at about 150 bucks. Check your local classifieds, ebay, craigslist, and honda marketplace to locate a oem system that someone took off to add a aftermarket exhaust. Ive come across sets for 20 bucks...just never when Ive needed an exhaust.

5)Ex swap is the way to go if your replacing the whole setup anyway. You'd need everything, but it'll save you down the line. as I said above, look for one that was taking off. If your in MN, your going to have the rust issue, but you never know.

cheap = find a top notch welder and have the manifold welded up. Your going to need a real deal professional though, not a kid with a harbor frieght welder. I know a guy who welds professionally, and his setup is in the 30k range. Expect a hundred dollar bill to fix and have it last.

tunerboy254

yea i just converted my hx (cat ehaust manifold) to a ex style exhaust sys. youll never find a cat manifold not crack. i have 2 hxs and their both crack. i wont recommend another cat exhaust manfold cause theyll crack again. i got a ebay exhaust and header for 230 shipped and a ex cat for 150 shipped.only down fall is, with the silencer its make a little buzz sound. my job requires me to drive alot and need all mpgs i can get. if your worried about mpgs dont eliminate the stock cat and replace with a test pipe. youll get a CEL and throw you car in limp mode and there goes your mpgs. for cost effectivness. goto the junk yard and get the complete ex haust system and relocate the O2 wires.

Jomyke242

Just found this:
http://www.partsgeek.com/z3gj7m9-hon...-manifold.html

What is the deal? Why so cheap?

Thanks to both of you for the help.

So for the EX swap - I can by any D16Y7 header and downpipe, and then it looks like the EX cat essentially takes the place of the the midpipe that is on my current setup.

I still have the damn clamped pipe from the cat-back. So replacing all of that to match the Ex setup kinda sucks. . . . .

If this partsgeek thing is really just $200 - maybe I do it and just hope the old downpipe and midpipe hold up with the swap .. .

tunerboy254

thats reasonable price and legit.

grumblemarc

iTrader: (4)

It's cheap because it's NOT OEM and isn't a "California" model. I'd hardly call it legit. Notice that the Dorman model is almost double.
http://www.partsgeek.com/9t6lpk3-hon...-manifold.html

beecee18

First f all to net the best MPG's from this vehicle you will have to address the issue of the cracked manifold. expecially if enough oxy is being introduced into the exhaust tract before primary o2. As this would most likely give you a fault(engine light/code) syatem to lean. This code adds alot of extra fuel to combat the excess of oxy in the air/fuel ratio. And can sometimes make your vehicle use gas at an alarming rate
And to make things simple, replace with new or known good used OEM parts that are for your exact make and model. new o2's would or could help if the existing were deteriorated at all.
There is not much that can be done to get better mileage then the factory built the car to get.
I would be more concerned with constant proper tire pressure,
problemfree driveline,
good wheelbearings,
and of course driving techniques that keep you in closed loop fueling (non-agressive) driving style.
to help net the best mileage

Jomyke242

So will I get 2 years 50K miles out of that part or no?

Of course it is a guess, but interested in your opinion.

If I was going to spend $325 on the Dorman, why not just switch to EX style with the cat under the car?
Seems this design with the cat hanging in the manifold is destined to crack again anyway.

Also, looks like a rusted mess to get this loose from the downpipe. You suppose I would just need to order that with this while I was at it?

thanks

furious94ls

I would try to find a COMPLETE used EX header/cat/b-pipe/muffler.

Jomyke242

I am near the twin cities, MN.

Craigslist didn't turn anything up.

Anybody got help for how I would track this down?
I like the idea.

Just start calling junk yards/part pullers and see?

Thanks!

C_Rock77

The problem you're going to have calling a yard is that it's against Fed Law for them to sell you a used converter.