Now that was interesting........................

Reset EML and light stayed off for a while but then re-appeared so decided to book in to have it checked on TECHII. All fine for that but car still drove all beit a little hesitant at time when more oomph needed.
Just been up to the coast to a job and thought when cars warmed up I drive along in 40 zones in 3rd gear locked up to 50 and then above that only 4th. My drive through the country was for about 35 mins but all the while the revs were kept above 2k in fact between 2500 - 3500 and you could smell/feel the car getting hot but needle still sat bang on 9 o'clock location. I then got that very slight kerosene smell and thought - oh it's going through a re-gen so I'll take the longer route and hang on in and see what happens.
I arrived at site with light still on and thought 'oh well - never mind - into garage'. Survey took about 2 hours; started car and light was gone. It ran as smooth as can be and revved to red line in sport mode and economy started going up so perhaps it has just solved it's own problem because no matter how hard I boot it she flies with no hiccups.
Just for piece of mind I'll keep appointment booked as light still needs sorting but will see how things go - only Shell going in now and every other tank will be V Power!