OK, so I decided to change out the stock muffler for a Magnaflow and did a delete on the resanator as well. I stayed with the 3" pipe; I could have gone with a 4" pipe but was afraid I would totaly lose my low end torque. For sure, the sound is SSOOO much better. Mellow w/o being too loud. So far, I don't detect any WOT difference in power, but hope to get a little mileage out of it. At least it doesn't "hiss" now when I give it the gas, pretty throaty.