[surfbeast]

I would guess they are running off road H/X pipes with cat back. If I had it to do over again I would go with the H pipe. I lost low end torque with the X-pipe or at least it feels that way. Also, I never had to use the MIL eliminaters on my OR pipe ( lucky me ). The OR pipes make a HUGE difference in sound, they would probably be loud with the stock mufflers!