My XX is stock with the exception of a set of cans. The FI light came on while riding after a period of the bike sitting up. It actually tried to stall on me while sitting at a red light.
I purchased some fuel injector cleaner and put that in with a tank of gas and it took care of the problem. I think it was the STP fuel injector cleaner that comes in a silver container. If I remember correctly, it's not just strictly for the fuel injectors and you add it just prior to filling up the bike with gas.
Anyway, it worked well for me.
Hope this helps.