This plug lets you unplug the oxygen (O2) sensor from the wiring harness to take the ECU out of closed loop mode. This lets the bike run in the rpm range of 13.2-13.5 AFR now, instead of the 14.7 area.
The check engine light WILL come on most likely, for awhile when doing this. It's just the ecu figuring it out. It will go away after a bit.
It works from idle to 6000 rpm, wehre the bike enters into the open loop mode. This lets you remove the O2 sensor from the pipe as well without siganling an engine code on the bike. The bike will run cooler, flame out and stall much less, and let you use our opened up exhaust end cap. This kind of mod may not be legal in your state and then would be for racing only. I know it's ugly with the silicone, but who cares becasue you don't see it, and you can't make this kind of gain for this kind of money amywhere.
THIS ONLY WORKS ON USA AND CANADA BIKES