Getting a downpipe w/ cat for my new headers

**Centauri** · 04-09-2015

I have a '99 GTP with newly installed Speed Daddy headers. I have yet to deal with the catalytic converter problem though. I was initially just going to have a shop weld the factory unit in but the SD downpipe is 3" and the cat is 2.5" so I thought I'd might as well go for a cat'd 3" downpipe from ZZP since the price seems pretty reasonable.

http://shop.zzperformance.com/store/...Downpipes.aspx

Until I saw this "This downpipe is not compatible with any aftermarket headers, it is designed to fit the stock OEM rear manifold."

What are my options then?

Thanks people.

**ItHurtz** · 04-09-2015

if you want a cat you have to have one welded in, there is no bolt on for sd's

**REDCRAPGP** · 04-09-2015

That downpipe isn't going to work with SDs. Buy a 3" cart hat is shorter then 11" or so (whatever the test pipe length is) and have it welded in its place.

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**BrandonHall10** · 04-09-2015

Here's the one Scotty ordered:

http://www.ebay.com/itm/360984770059...AIT&rmvSB=true

**Centauri** · 04-09-2015

My god that's cheap. I thought cats were supposed to be expensive because of the raw minerals used?

Anyways, that seems perfect. So my only question then is where does the o2 plug in at?

**ItHurtz** · 04-09-2015

you have to have a bung welded in

**Scottydoggs** · 04-09-2015

sd headers come with the o2 bung in the small part of pipe with the flange on it.

thats the cheapest cat i could find, free shipping even.

**Centauri** · 04-09-2015

Thanks.

I notice he lists a different part for 98+, which did you get?

You kinda have to wonder, given the price, if these actually work anywhere near as well as OE... Hmmm.

**Scottydoggs** · 04-09-2015

who cares if it actually works lol i need a cat installed, end of story, thats a 3 inch cat. its going in.

im getting the one in the link there, i have speed daddy headers, they have a 3 inch down pipe. im really hoping the cat will just replace the middle section of pipe in the down pipe. if im lucky enough i can clamp it in, then weld it later on when i have the engine out.