To clarify, the ecm will use the 02 sensors to adjust in low rpms. After that the ecm takes over and the programmed fuel and timing maps, which were made "exhaust configuration specific", take over and deliver the programmed amounts of spark and fuel. If would be wise to get a programmable ecm from IDS and dyno tune the bike for that new style of system. You don't want it blowing up on you at high speed, thing get ugly quick.