I go with what Josh said. On swapping out the standard exhaust for an SC Projects I was not to happy with how it ran as the ECU is programmed for the stock set up. Eliminating the 02 sensors to get rid of that closed loop circuit and adding an after market air filter and remap....the bike runs better and picks up speed better. I have no way of proving this but then I do not feel I need to. All I know is when bike was in for last service and I took out a demo scrambler the difference was obvious.....