On my 2007 Wing, I took out the baffles and cut off about 6 inches, and reinstalled. The sound was so boomy it resonated in my helmet. Welded the baffle back together. Then bought TorqueLoopz, and cut out the cat. Sounded and ran a lot better! But still something missing in the sound department. Put on Cobra tips with the Loopz, and voile'. It sounds great! Not too loud, but smooth and yet growls. Only growls when hard on the gas. The power gain I have now is surprising. The torque curve is different; as it pulls strong right up to redline; (not that I do that on a regular basis). As we all know, we shift by feel rather than watching the tach. And the Wing flattens out 3000 - 3500 'ish. First time going through the mountains, I could not believe the strength of torque, and when I glanced at the tach, it was almost redline. I would not have believed it if I didn't experience it myself. Now that I am about to trade in on a new Wing, I doubt the dealer will take it on trade with out the cat. Go guess I will go to eBay. Just thought I would share...Keep the rubber side down!