I have a 2004 wrx wagon, Im going to be putting on a turbo back exhaust this summer. Looking at a clear sounding, quiet-ish catback, and then putting in the downpipe. My local tuner has a couple 3" bellmouth downpipes that fit perfectly but they have no cat attached. Do I need a cat on my downpipe for MA emissions testing? I'll still have a cat by the midpipe, but do I still need the extra one like on stock or the Cobb downpipe?
Any Mass people, please feel free to reply.