Ok, stopped in today and he said it sounds like a miss, put a scanner on, I don't have any codes but he was able to do a live read of each cylinder and 2 and 6 have a few misses. Odd that it's not throwing a code, and odd that I drove 8 hrs this past weekend from Ohio to Indiana and back, with no performance issues or indication of a miss other than the exhaust sound. I have a lifetime warranty on the wires, which I changed in January. I picked up some new wires today and I'm going to try switching them out to see if that could be my issue. If that doesn't work, he said bring it back in and he will gladly go over all the joints to check for a leak or something along those lines.