Thanks to Mark, Tony, Scott and co.
CEL came on on way back from Goodwood. Just turned out to be rear Lambda sensor - now turned off.
But also great coffee and chat covering everything from A40s, Minis, Escorts, 370s manual and autos, GT86s, Elises, etc, etc.
I could actually spend all day listening to that stuff
You tend not to get that at your local Dealer