[The legal crap from my lawyer, Susan Moore with Dewey, Cheatem & Howe]
Doing this mod to your truck is illegal, and I claim no responsibility if you do this to your truck.

With allot of time on my hands lately I've been trying to do some simple mods to my truck; I've wanted to euthanize my kitty for some time now...but I'm not in the position to go with a 4" Turbo back. I had been looking around locally for 3.5" pipe so I could just have a muffler shop delete the cat...no one carries it. I didn't really want to shell out the $75 for a piece from an aftermarket exhaust company. A buddy suggested going to a salvage yard and getting a piece of straight exhaust off a wrecked SD. So a couple of weeks ago I went to one of the local yards looking for PSD powered SD. When I got out in the yard I discovered a '00 extended cab SD that had a straight pipe under the cab where my kitty was on my '04. I paid the man $20 and I came home with the straight pipe you see below:


After comparing the two side-by-side I discovered the one from the '00 is about 6" longer than the one from my '04. If you go to a salvage yard...your looking for a '99-'02 SD with the automatic tranny (4R100?). From what I've been able to figure out from our fellow SD owners in the 7.3L forum...the trucks with manuals had the kitty cat; as well as all the California trucks. The slush-box trucks didn't have the kitty until the 6.0L started to appear.

With the help of a buddy (the pipes are awkward to handle while laying under the truck) we removed the OEM pipe from my truck and bolted the '00 in it's place. Both are the exact ID/OD and the donuts is the same on the engine end. There is a slight difference where the exhaust hangers are. On the muffler end I'm not going to worry about it (there is two hangers within 8" of each other ahead of the muffler) and the one by the do-nut is close enough that the "dog bone" can reach it...just isn't straight up and down like the OEM set-up.



Looking back toward the muffler....



It took us about 2 hours to do all the work which included fighting with getting the pipe out of the muffler; cutting the excess pipe off the '00 and bolting everything together. All the bolts are 15mm, and came off quickly with the help of an air ratchet. I haven't checked my mileage yet to see how much it's come up. But my turbo is noticeable when I "gas on it" and there is a very faint rumble/turbo whistle when the truck is idling. Something to think about if you want to loose the cat but don't have the $$$ to shell out for an a/m system or delete pipe from the a/m guys.

 

That is a great money and time saver,thanks for sharing.

 

Somebody need to come up with a straight pipe with a kitty look alike on the outside.

 

Here's something I have seen done before. If you want to delete and make it look like nothing has been done, take a piece of pipe or metal rod slide it down into the exhaust pipe pictured above and hammer the crap out of it. The cat is made up of a ceramic material that is hard but starts to crumble after some good whacks. Keep repositioning and pounding it in until all the ceramic is out.

 

Yep, the earlier 7.3L had no cat and the pipe bolts right up. I looked at buying a new one, but fairly steep. Didn't think about the salvage yard, guess I'll take a look. I have an extra cat though, so gutting one would still leave it looking stock.

 

I spent some time in the 7.3L sub-forum trying to figure out which trucks did and didn't have the kitty. The best I could tell the slush boxes ones were the only ones that never had kittys...with the exception of the CA trucks. All the gear-grinders & CA trucks had 'em. I was impressed how easy it was swap between the two different model years & engines; clearly Ford didn't change much between the years.

 

thats easy just run a pipe thru your old cat
Im not sure there is any benefit but i was told you should run a pipe thru the old cat. Maby it sounds better.

 

There can be some odd resonance with gutting the cat, so running a pipe through it is recommended.

 

Unless you think a "visual" inspection is required, I wouldn't ruin a perfectly good cat converter!!! Those things are expensive!!!! Replace it with a straight pipe and if you NEED to put the cat back on, you won't have to shell out big bucks.

 

I am told there are places that will pay good money for used cats. There are expensive materials inside that can be recycled, just a thought.

 

They have platinum in them I beleive.

 

I took mine off my 06 and took the guts out of it. I took my Hilti drill with a 24" long bit and drilled the ceramic full of holes. Then took a long shaft and knocked out the remaining ceramic. Made the turbo sound different but can't tell any performance change.

Dan

 

this is the straight pipe i had welded in,

 

yep,, i gutted my cat and then was told the exhaust air is flopping around in there so i was wondering if just a straight pipe would sound better. so,, took a pipe thru the converter and welded it in place,, and made it sound a lot better for me. when i got it inspected the guy said as i rolled in,, (its noisey) and then he looked under and said, "but you got the converted on".. paid the man and left with a new sticker..lol..

 

No hijack here just somthing I know a little about. I have a buddy that makes a verry good living on buying and selling cats. Some cats have some rare metals in them he will pay upto 350 400 for one, usually a bmw or forien job. I dont know whats in a diesel for material but guessing its 30 bucks or less.