Quote Originally Posted by Scottydoggs View Post
the rear o2 should be in the same place in the down pipe. its not headers, its just the down pipe and cat then it bolts to the resonator.
The rear o2 is a little further back on 03- than stock on 04+, that's why the extensions exit. Since everything pre-cat is the same, they didn't bother making the bung further back on piping.

I can't think of a reason that the extension wouldn't work 06-08, unless the wiring harness is different. If you wanted, you could go to an exhuast shop and have the bung that comes with the downpipe plugged and a new one put in. That gets rid of the issue all together.