OBS downpipe cat delete question.

Bulletproof7.3 · Dec 3, 2012

Ive been searching on here for the last half hour and cant find anything for what Im looking to ask.

so...
Looking to leave the original exhaust on my obs 95 but I want to get rid of the factory downpipe and cat.

What all do i need to buy for that and how much are they going for?

Thanks guys.

backwoodsboy · Dec 3, 2012

Going to need a 3" to 3.5" bell reducer to couple the DP to the stock exhaust. Then a section of 3.5" straight pipe and a couple clamps to delete the kitty. Both should be fairly cheap at a local parts store or exhaust shop.

94.5 Stroker · Dec 3, 2012

Just need a down pipe and a cat delete pipe i believe, the bigger exhaust doesn't step till after that

Bulletproof7.3 · Dec 3, 2012

Is there anyone that sells a kit for what im looking to do that you guys know of?
Delete cat and add new down pipe, while leaving the existing muffler and orginal pipe from the deleted cat back.

When i look at some online it looks like there is a down pipe and delete pipe but im not sure how the two connect together because the one end has a flange, and im guess the bell end of the other slides onto the down pipe .

Magnum PD · Dec 3, 2012

Have you checked Ebay?

http://shop.mobileweb.ebay.com/sear...sort=BestMatch&mfs=GOCLK&acimp=0&isNewKw=true

Bulletproof7.3 · Dec 3, 2012

Yeah i looked at those but it looks like i need to buy 3 different pieces and only 2 come in that deal. Im not sure if im looking at it wrong or what.

there is a down pipe and then the other pieces that comes with the down pipe, and then i need another cat delete pipe? Why wouldnt they sell all 3 together? or am i looking at this wrong?

Magnum PD · Dec 3, 2012

3 pieces is normal. If you talk to one seller, maybe he can cut you deal.

Bulletproof7.3 · Dec 3, 2012

Yeah i could try to do that. Ill call someone up tomorrow. See what I can figure out, If anyone wants to deal that looks at this in the next day or so, PM me and we will see what we can figure out.

Thanks guys appreciate it

davey99ps · Dec 3, 2012

I'd check with Paul at Complete Performance, he's a site sponsor and an obs nut, I'm sure he can get ya taken care of with all your needs

old man dave · Dec 4, 2012

The stock muffler is 3.5" inlet/outlet, so you need a OBS 3" downpipe, a 3"to 4" bell adaptor and a length of 3.5" exhaust pipe. Also some exhaust clamps, exhaust bandclamps work the best (can get these at NAPA). 1-3" and 2-3.5"clamps. You may also want to gut out the exhaust Backpressure Valve.

The stock muffler is a straight through design, not that restrictive. I pulled 408 hp through the stocker myself.

85_305 · Dec 5, 2012

old man dave said:
The stock muffler is a straight through design, not that restrictive. I pulled 408 hp through the stocker myself.

But the cat is terribly restrictive, which is the piece that he's wanting to keep lol.

woodduck97 · Dec 5, 2012

85_305 said:
But the cat is terribly restrictive, which is the piece that he's wanting to keep lol.

It clearly says in his first post he wants to get rid of that. :lookaround:

85_305 · Dec 5, 2012

:doh:ya

Cowboy Troy · Dec 5, 2012

I just hollowed out the cat on my obs so it will pass a visual inspection.

Bulletproof7.3 · Dec 5, 2012

yeah i found everything online that i will need.. I do want to get rid of the cat and leave the muffler. Im hoping the downpipe, the cat removal, and a ts 6 pos chip will really help my fuel mileage.

Im getting about 17-19 mpg now , hand calculated . Hoping to be in the 20s after that

Thumper97 · Dec 5, 2012

MBRP makes a good 3 in down pipe for them kit # is DA6218 they go for about 95 bucks and will put the outlet right where your cat inlet is. just add your cat delete pipe and you're in business

old man dave · Dec 5, 2012

The cat is the worst piece in the exhaust system. After that, the EBPV should be gutted out.

After the downpipe, you only need a straight section with adaptor bell to the muffler. Cheap tailpipe is a Walker 55102 availiable from Summit Racing for less than $50 bucks. Its a 4" so you would need a bell reducer from the muffler to the tailpipe. Make your own hangers in the same style as the stock hangers and weld them to exhaust clamps to make them easily adjustable/removable.

Actually at this point, you could just get a 4" in/out muffler and you would have a true 4" exhaust without using reducing bells. Need to get a muffler intended for diesels though. Or straight pipe it.

Bulletproof7.3 · Dec 6, 2012

Got the 3" down pipe to 3.5" cat delete. Going to leave stock muffler for now and keep it decently quiet.

Is there a way to unhook the EBPV like there was on my 00 7.3? I just unplugged it at the white plug before.