Check the vacuum hose to the Pb sensor near the top of the frame above the engine.
Yes you will see a vacuum line going to them. No, you do not have to remove the fairing.xlnt, thanks very much, i can do that, and that sounds the most plausible cause.
will i see a vacuum line coming from the injectors up to the sensor so i can identify the sensor, otherwise how will i know the sensors when i see them?
also, does the front fairing need to be removed to remove the fuel injectors?