I've been trying to find the part number for a Walker downpipe for my I-6 300. I'm putting the FI model exhaust manifolds on and need that downpipe. The part number I got from Walker, 15739, is the downpipe and cat. Napa wants $301 for this and all I need is the downpipe. Neither Napa or Walker say they have a part number for just the downpipe.

Anybody have the part numbers or any ideas?

(I found mention of the Walker downpipe being about $50 when I did a search about a week ago, but now I can't find that thread.)

Thx - Drew

 

I found it. Anybody that needs it #45166.

 

what company can you get it from? thanks.

 

I've found that I can get it through Napa. The cost is almost $100. I'm trying to find it someplace else for less $$.

 

Try Advance Auto. I got mine for around $65 I think.

 

Thank you! I was able to order it online at Advance Auto Parts. (partsamerica.com).

They sell the Dynomax version for $64.99 and the Walker version for $54.99. Both use the 45166 part number.

 

thank both of you for this useful info!! that's a big differance in price.

 

Does anyone know if that downpipe will fit right into a 67 thru 72 bodystyle F100 pickup? When I put in the later model split manifolds into my 67, I had a little difficulty with the downpipe, and had to have the muffler shop help me out. They charged me alot, and didnt really do it right. I salvaged the downipipe, along with the manifolds out of a van however. jz

 

Walker and Dynomax are the same company. I have their car and truck catalog and Dynomax is listed in the back for light trucks!

The downpipe number is 45166. That fit my 1982 F250 4X4, 300 l6. I installed the split EFi manifolds and ued that with their universal high flow cat.

If you have or will use an O2 sensor it has a bung welded on. Other wise you will need a plug for the hole. I used an O2 sensor and bought a air/fuel meter!

If you need other walker numbers I have the book.

 

Do you have the part # for the high-flow cat? I know I'm going to have to put one one before I get my emissions test.

Thx

 

Sorry to dig up an old thread But looking for an efficient way of replacing my downpipe/cat without spending a small fortune at an exhaust shop. So, my question is, does this downpipe effectively "remove" the cat. from the exhaust system, or are these just the pipes in front of the cat? Any help would be appreciated. Thanks.

 

The downpipe just connects the two EFI exhaust manifolds and combines them. This would be before the cat. It was pretty easy for me to just install new pipe from there to a muffler and then exiting just in front of the right rear wheel. (I didn't bother putting a cat back in.)

 

Get one from Partsamerica.com [advance], they're $65 and free shipping... usually no tax. My local wholesale place charges $56, so that's a deal. You could also get the factory "Y" from a truck or van. Its more a dual downpipe setup that a "Y", and will flow better than the Walker part if set up properly. Also be prepared to do some grinding on the Walker part, many people report the welded on rear connector enters the main pipe thru a jagged poorly shaped hole.

 

Thanks a ton for the info. But that leaves me with another question, sometimes I can be a little dense . Basically this is the downpipe section, got that much, but there are 2 pipes going into the cat? Soooo... is the spread a common spread so I can just pick up pretty much any Y pipe to bring it down to one tube so I don't have to do the whole duel exhaust setup.

Just so you know where I am coming from with this, I am looking to remove the old converter, still use single exhaust, and be able to get some pipe/muffler combo together to do this myself in my garage. But if the downpipes don't have an "effective" Y pipe I can use to bring it back down to one pipe I might just have to shell out some cash to go open headers to the exhaust shop for them to do it

'89 F150 Custom - Regular Cab, 2WD, 300 CI

 

The walker part is basically a single pipe that reaches from just behind the tranny crossmember up to the front EFI ehaust manifold. There is a second stubby pipe welded to this that connects to the rear manifold. The factory "Y" has two separate pipes that join at the pre-converter beside the transmission.

The walker pipe is more like an old school "log" style exhaust in that you go from 2 into 1 right at the manifolds, so both are sharing the same 2.5" tube all the way to the muffler. The Factory Y is more like headers in that the two manifolds don't merge till much further down. The stock EFI exhaust system had two converters, a small "pre converter" that also serves as the 2-into-1 collector, then a second main convertor a couple of feet behind. You can leave the pre-convertor in place and use the single 3" pipe that exits it to connect to your muffler. This is what I did since everything's ready made and the pre-convertor isn't very restrictive. You could also just gut it if you don't have to pass emissions, or cut the pipes right at the pre-convertor and join them with a generic 2 into 1 collector [about $15 or make your own].

The walker pipe might be a touch easier to install, but it's $65 and will need some cleanup to work properly. The pipe is also made with cheap compression bends so the flow is restricted by a smaller diameter and creases in the pipe. The factory Y can be had for $20-$30 from a scrapyard and will flow better. The pipes are nice smooth mandrel bends and each manifold has it's own 2" [maybe 2 1/4"] pipe all the way down to the convertor.

There are a couple of good pics of the walker part posted on this forum, just do a search to find them or I could email you one. I'll be pulling my exhaust [w/ the factory Y] soon to port match the manifolds to the head, and I'll snap some pics of it when I do.