Hi Gregg BMW K1200LT O2 Sensor. Thanks for your answer. Both Failures occurred during normal riding, is there a way to test the sensor as I know they are extremely sensitive regards Alan

If you can get the specifications they can be tested
( best done by a service center with the equipment)
generally a clean using vinegar will remove the oxide build up that affects their performance unless it is a wiring problem in which case , replacement will be required
be careful as there are 2 oxygen sensors in use
one has 4 wires and is a heated oxygen sensor and the other is an oxygen sensor with 2 wires