My 2005 MV Agusta runs rough only sometimes. Once the engine is thoroughly warmed up it begins to act like its not firing on all cylinders or running rich. It becomes very sluggish. It smells like unburned fuel during this time also. Tried addding injector cleaner thinking its a fuel injector not properly spraying. Didn't seem to work. Thinking maybe O2 sensor?

First may I say Nice bike,I own a gsxr 1100 and love it....But I bet that is knee dragging heaven.Your really need to plug a laptop into the computer on your bike to figure out whats going on.But your on the right track thinking its a o2 sensor.They make programs you can buy to diagnose problems with your bike.I am not sure for that particular bike where you can purchase it but if you Google it you will come up with somthing.Or you can purchase o2 sensor if not to exspensive and start there.The problem with the newer bikes is everything is controlled by the computer and you can really go crazy figuring out whats wrong.This could be a sensor,fuel injector,fuel pump,spark plug or any of the ingition components.Good luck but you may have to bring to dealer. PS Rubber side down and ride safe....BC