it's an '07 for sure. The '06 800's were not running an O2 loop. There's plenty of O2 sensor bungs available on the interweb, but they're really no more than you've prepared for with an appropriate size nut. I've got to believe that any competent muffler shop can handle it in no time. Just be sure to mark the pipes so that you don't come home to find you've got a placement / clearance issue AND a freshly threaded hole in your header.