Yep! I've swapped over each part and tested on the other bike which still runs fine.... including things like temperature sensor, throttle position sensor, injector, spark plug, throttle unit... And the last part I've got left is the O2 sensor, both bikes shows engine light and O2 sensor code, which is quite usual for both to go at the same time. They are 4pin sensors and they have been checked with a multi meter and it seems both have out of tollerances, does not produce more than 0.2V when heated being red hot, and poor ohm reading on the heater part. Will order one in and see if that solves it!