Mike
Thanks for your reply. Do let me know. BHM suggested a check of the pipes connected to the charcoal canister as they have been known to leak, self seal and leak again because of rough roads, even coming adrift entirely. One can access the canister by undoing the luggage rack bolts and removing the rear undertray followed by the cover. One just needs to raise the rear end- put it on ramps for easier access.
I do have a service sheet from the previous owner which shows a reset of the code indicating 02 sensor Bank 1 Sensor 1 (Lambda Sensor required) at 5139 miles.
I am now at 8400 so I wonder if the sensor was changed as I bought it at 5300 in November. However II note that you still have the MIL light even though the sensor has been changed.