I've Got the fiatmultiscan software and reader but in Macduff
Portland Bill - The white smoke is immediately after a cold start, and then dissipates within a minute, or so, and it is gone until the next cold start. Would that match your injector theory? Anyway, I'll have some Redex in there shortly and will see how that goes. If no joy with that, I'll have a look at the boost regulator and boost valve.
Does anyone know if the light will simply go off once it is happy, or will it stick until it is told to go away?
To try to get MES to work with your ELM, have a look at this thread, specifically my post, post number #5 . Try that procedure, hopefully that will work. Sadly, MES forgets the settings when you close it, so you have to reset every time. https://www.fiatforum.com/panda/352156-fiatecuscan.html