will an o2 housing w/ a 2.5" flange bolt up to my stock downpipe??

[futurevokiller]

so i just got a 16g that i plan on putting on this weekend along with a fuel pump. first off my car is all stock other than intake, 2g maf, and evo injectors. the pump and turbo will be my first time for both mods, so any tips would be appreciated. my main question is about the o2 housing on the turbo though, it has a 2.5 inch outlet, and im pretty sure my stock dp is gonna have a 2.25 inch flange on it right? will it bolt up, or am i going to have to like weld a 2.5 inch flange on it, or better yet, if i just bought an aftermarket dp would it bolt up to my stock cat-back? im on a very tight budget and couldnt afford a whole turbo-back exhaust at this time, but could probably get just a dp if that would solve the problem. anyways, thanks in advance!!!

 

[DroopYeyeS]

Many times the flange will line up, and bolt up. The real issues is the turbulence caused by the change in I/D of the passage. If it will mount to your new turbo ( which it should ), I'd use the stock o2 housing for now, then put the new one on when you can change the rest of the exhaust. Just a thought.