Hello. I have a 03 r6 that I bought this spring and have put about 3k miles on it so far. It came with a stainless gytr slip on exhaust with no power commander. That is the only motor modification. So here's the deal. Since I've had the bike, about once a week it would die on me when I'd pull the clutch in to stop or downshift for a turn. The rpm's would just fall all the way down till it killed. It would start right back up everytime and be good for about another week. Now it has progressively gotten worse, while I'm riding I can hear it sputter and pop and it feels like I've dropped a cylinder. Major loss of power and is really jumpy, only runs with the throttle applied. When I turn the key off and then back on it will run fine for only a few miles then turn to crap again. My gas milage has cut in half (no lie) and it just wreaks of gas while it idles (when it does). The exhaust tip is caked with soot. So tonight I throw on the stock exhaust and for the first time in awhile it ran like a champ the whole night, ran clean and the smell of gas was hardly noticeable. My questions are: Anyone have this problem with just a slip on? Do I need a power commander? Or is there anything else that could contribute to this problem? Any info will be much appreciated! Thank you!