Electrical Plug

It’s not terribly important and your bike will run without it. All it does is release air via that solenoid valve from the airbox into the exhaust in order to clean up emissions and burn any unburnt fuel in the exhaust gas. It’s what makes that popping and banging when tha shut’s throttle. Many have disabled the SAI in the Tunecu menu and blocked the tube with a marble so it doesn’t pass any air to the SAI valves. Alternatively you can purchase custom made block plates to remove the SAI valves, there’s one for each cylinder, and they look and work a bit like the reed valves in the intake of a two stroke Yamaha, ie pass air in one direction.
Other than that, I don’t know sod all abart em.