I rode mine a 2013 XCT no mods for a year or more with no engine light. Our system is kind of "old school" when it comes to engine management. When disconnected it defaults to the "rich" side. So I did it trying to get bike to run a bit cooler. I didnt feel as it actually did. So I have them hooked up again. I really didnt notice any difference one way or the other. I will run more effeciant with them connected as it can adjust fuel mixture.