The C90 is amazing. Great ride, great power, easy to control, secure feeling on the highway with almost 700 pounds. But the sound from the pipes leaves something to be desires. I choose to ride on the highway with a full face & visor helmet and above 40 I find it hard to hear the bike. This is my first bike so yes I need more experience and already after 250 miles, I can start to feel the bike as opposed to need to hear it. But if I cant hear it well, anyway I just want to beef up the sound. I have read allot from the 05 discussion group, but with little experience is parts and mechanical knowledge, can someone point out exactly what pipes and mods would be necessary to get a bigger sound. I also experience the backfiring at deceleration and donĀ“t know if it still would be a sensor issue or not. Any guidance would be greatly appreciated.