I've thought about this too. If their FI is set up like a car then then there is a mass air flow to measure air as it enters the engine. I'm not sure of this, this is the first FI bike i've ever had. Everything else has alwasy been carb. I've hit the 1000 mile mark and i need to do the 1k mile tune. I'm going to do it myself and try and save me the 300 bucks. To get to my point, I too found it odd that they don't use the 02 sensors.