I add a 2nd muffler & pipe on the opposite side from the cats,our factory muffler's very big,so my mech just went with smaller mufflers,like half the size of the original one;the sound is amazing & the torque increassed around 30%,i have no technical info about the brand & model,i'll check that with the mech this weekend so you may add the same set up.

I had my annual emission done saturday last week & passed with excelent results over the machine.