Where can I find a new exhaust y pipe???

amberbrush · Post by **amberbrush** » Mon Jul 09, 2007 7:19 am

O.k., if any of you have been following the posts I have tried numerous attempts to repair my Bronco II's lack of power problem with no luck. I finally just installed another 2.9L engine and had to cut off the exhaust y pipe because it was rusted so bad to the manifolds. Where can I purchase a new y pipe? I haven't been able to find anything on the internet. I just want the same thing as factory so it will be cheap.

CraigK · Post by **CraigK** » Mon Jul 09, 2007 9:26 am

amberbrush

Sorry to hear you were unable to work out the problem on your existing engine. Can't help you with a Y-pipe supplier (yet), but would ask a favor . . . if at all possible

What is the outside diameter of the Y-pipe exhaust pipe at the location closest to the exhaust manifold flange? (where it is a single pipe still) And if you could, what is the bolt-to-bolt distance on the flange that connects the Y-pipe to the exhaust manifold?

Thanks.

CraigK
P.S. When you locate a Y-pipe supplier, could you please post on this forum? Thanks again.

Paul · Post by **Paul** » Mon Jul 09, 2007 6:37 pm

i got one at the house ..... in the garage
but i found that the y pipe for a 91 explorer 4.0 is identical to the 2.9 .....

you pay shipping cost, ill sell you my extra from when i did my engine swap .........

Paul · Post by **Paul** » Mon Jul 09, 2007 6:39 pm

when i get home i will get those measurments and post them for you ..... currently I am at work

Paul · Post by **Paul** » Mon Jul 09, 2007 6:41 pm

well i hope you got the problem fixed with the install of a new motor.

CraigK · Post by **CraigK** » Tue Jul 10, 2007 3:37 am

amberbrush

If you don't end up buying Paul's Y-pipe, they are listed online as being available at AutoZone stores and online. (www.autozone.com) The Y-pipe for an '87 w/ 4WD is part# 439855, and cost is $80.99.

CraigK

don't know if this link will work directly:

http://www.autozone.com/R,APP1090421/ve ... Detail.htm

amberbrush · Post by **amberbrush** » Tue Jul 10, 2007 6:45 am

Paul - How much do you want for your y-pipe? I suppose I would have to know shipping as well. I am located in Nebraska. Let me know what you come up with.

I will also check AutoZone and see what I can find out.

amberbrush · Post by **amberbrush** » Tue Jul 10, 2007 7:12 am

O.k., I looked at AutoZone and they do have y-pipes. There is two different styles. The 1986 and 1987 are part #: 439855 and the 1988 and 1990 is part #: 430006. They are each a little different to match the two different types of converters.

Now here is my question...

I have a 1988 Ford Bronco II with 4x4 and would like to bypass the cat. converter. Would I go with the 1986/1987 y-pipe since you could run two pipes off the openings into one? Or possibly dual exhaust? I noticed on the 1988/1990 y-pipe the end is made for the cat. converters oval opening. I don't think you could find an exhaust pipe to fit this end. If you can let me know where you can get it. Looking at the 1986/1987 y-pipe it appears the ends are perfectly round and you could just hook the rest of your pipe to it. Let me know what you think or if anyone else has done this.

CraigK · Post by **CraigK** » Tue Jul 10, 2007 8:04 am

They don't make this easy, do they? (bypassing the catalytic converter)

As my '87 B2 is 20 years old, it now qualifies in MD for registration as a historic vehicle, and will no longer have to pass emissions tests every two years. As my Y-pipe may not be salvagable (flange completely gone), I'm on the same repair track as you amberbrush.

It looks like both the 86-87 and the 88-90 engines use the same manifolds, so I would guess both Y-pipes would fit to the exhaust manifold ends equally well.

The issue then becomes how to rig up a catalytic bypass pipe. Despite it looking easier to rig up on two round holes, I would hesitate to carry the 86-87 system back as separate sides (dual exhaust system), as there is likely some exhaust "tuning" effect. (FYI - if you don't know - this is when individual exhaust pressure pulses from one cylinder effectively assist scavenging of exhaust from another cylinder. I'm not sure if there is a tuning effect with these engines, or how much, or how this influences the EFI system, but it might be asking for trouble. An option for the 86-87 Y-pipe might be to then have both pipes enter a common muffler immediately past the Y-pipe.

Alternately, using the 88-90 Y-pipe, it might be possible to use a round pipe by carefully shaping it into an oval. This might be very tough, given it will likely need a 90° lip for the flange to grip and hold it in place, or creation of a custom flange and welding.

I think the answer might be in the availability of two-pipes-in, one-pipe-out mufflers. I'm gonna look around. The diameter of the individual pipes on the Y-pipe is important for this.

CraigK

Paul · Post by **Paul** » Tue Jul 10, 2007 6:47 pm

in 1989 ford changed the heads on the 2.9 liter. i used my 2.9 liter stock y pipe on a 1991 ford explorer 4.0 v6 motor ........

as for the question for the manifolds, yes they are the same, i also believe that in turn you will find that the problem with duals is the front drive shaft is in the way ....... or so im told .....
i believ you may find that the difference in the two parts might be with the 02 sensor positionong, and the fact that some broncos came with 1 catalytic converter and some with 2.... mine was the oval style that has 2 catalytic converters...... asfar as cost ill take $20.00 for the y pipe and what ever the shipping cost is.....

alternative ........ check the 4.0 v6 for a 2 wheel drive (explorer 1991 model) in a junk yard.

Paul · Post by **Paul** » Tue Jul 10, 2007 6:58 pm

http://www.cardomain.com/ride/315273

check here it will show the difference in the head styles

Paul · Post by **Paul** » Tue Jul 10, 2007 7:02 pm

you will notice the angle for the forts on the exhaust manifolds is slightly different, it may affect the way the y pipes were angled to attach to the manifolds, but i am unsure of that, so dont take my word for it that they wont work....... the only difference in them may be the collector for the catalytic converter and nothing more as you mentioned.

CraigK · Post by **CraigK** » Wed Jul 11, 2007 4:36 am

Paul

Crawled under there yesterday . . .
Looks like my Y-pipe itself is still OK, good for another year or so. Except that the flange is almost completely gone on the passenger side, and starting to go on the driver's side. (These flanges seem to be just pressed sheet stock, so they rust away easily.) The good news is that there may be a "split flange" available. It comes in two pieces that bolt together around the 2.0" O.D. Y-pipe, and then can be slid into place (I hope) and the manifold-to-Y-pipe bolts replaced and tightened up to stop the leak. My catalytic converter is probably not converting too much anymore, but it's structurally intact, and probably good for another year or so too.

However, I'm not sure if the bolt pattern on the split flange will match the holes on the exhaust header,

and I can't get down there to measure properly. The split flange is special order, and costs $30 + shipping, so I want to be sure it will work before I order it. Paul, would you mind measuring the center-to-center distance between the two bolt holes on either the exhaust manifold or the Y-pipe (where they fit together), and posting the measurement? It would be greatly appreciated.

amberbrush
Looks like the two individual Y-pipe pipes are 2.0" O.D.. I wasn't able to find a muffler with two 2" intake pipes on the internet (you have to first specify make, model and year to get images), but I think the guys at the local muffler shop or auto parts store might know which model #'s might be like this.

CraigK

Paul · Post by **Paul** » Thu Jul 12, 2007 8:53 pm

i will check the dimensions when i get home and post themfor you.

as far as a muffler with 2" inlet check the 70"s model comaros ...... i believe they run dual inlet and outlets.............. but can't guarantee that .....

i will try to remember to post the measurements for you here tomorrow...