Originally Posted by Staged07SS

It will not bolt up to the stock catback.

The exit flange is much larger than the stock catbacks 2-bolt flange.

Also, the stock catbacks entance to the resonator is only 2 1/16", so even if it did bolt up you would potentially have an exhaust leak due to the much larger diameter of the random tech downpipe.

ZZP will weld on a spun metal cat if you ask them to. They just did that for me Plus ZZP uses an interlocking flex section. Random Tech uses a craptastic braided wire mesh flex which ends up warping do to the heat from the exhaust gases and chokes the flow off. Ask me how I know I'll try to find some pics of what it did on my car.

Originally Posted by 05RLS2

Looks like I'll be getting in contact with ZZP then to see if they can build one for me in 2.5". Have you experienced the p0420 or any other 02 related emissions codes after intalling the ZZP DP with the metal matrix cat?

Do you happen to have any pics of the ZZP DP uninstalled or installed? I am just curious to see how it looks.

Originally Posted by 06cobalt racer

the stock cat is a high flow......but all the restrictions in the pipe is where u will see the improvements. i.e. where the o2 sensor is.

Originally Posted by 05RLS2

Does ZZP use the interlock flex on all DPs, or did you specifically ask them to use one on yours?

Originally Posted by 05RLS2

Well, after contacting ZZP they told me that all Ecotec catted downpipes come with spun metal cats. Magnaflow spun metal cats are supposedly an option. Did you go with the standard spun metal or Magnaflow spun metal? I am wondering whats the difference in the two

Originally Posted by Staged07SS

Hmmm that's news to me. The standard cat has always been the ceramic core cat. All of the the cats they provide are made by Magnaflow (fyi).

I went through a few e-mails with Tim, Steve, and Zoom about adding some things to my downpipe. They told me to add a note in the comment section "spun metal cat please".

I think they messed up what they told you man. I had a ZZP 3" downpipe a year or two back, and it came standard with a magnaflow ceramic core cat.

Originally Posted by SneakyMilo

I think the standard cat for their long tube header is spun metal, maybe that is where the confusion is coming from. I also just ordered a DP from ZZP and the standard cat is ceramic.