Hi! If you disconnet the oxigen sensor you will have a problem will burn alot of gas (Drinker), the oxigen sensor controls the gas that go's thru the FI, if your bike start to burn to much gas the oxigen sensor will send a signal to the computer telling the computer. that the engine is burning to much gas and then the computer will reajust the FI with the right amount of gas that the bike realy needs, hope this helps.