Ok I did a search couldnt find much on this. What I want to do at this point is get a custom test pipe made that goes in place of my stock converter on my DX hatch. The reason for this is because I have a swap and just installed a new header with the JDM 2.5" collector size. I want to continue running my stock civic dx exhuast with my new header (i know its dumb but oh well I have my reasons). So the test pipe is gonna have to go from 2.5" down to whatever the stock exhaust size is.

Does anyone have pics of something like this or have on that they dont need anymore let me know. Im very interested