Hello to you all. I’ve just joined the club as an owner of a 2014 1.6d titanium and my son has an ecoboost. 
I mostly do my own servicing and mechanical work on the car as well as another vehicle I own. My son is a student in Glasgow and his 1.0 ecoboost is showing the fault code P0420 bank 1 indicating a turbo fault, but I live on the Isle of Lewis so I’m of no help to him in fixing the issue. 
Neither of us know any mechanics/garages in Glasgow  and I’d be grateful if someone could suggest an independent trustworthy competent Fiesta mechanic who could rectify the fault.
Many thanks.

P0420 is a knackered cat, not a turbo fault.  Tell him to try a can of cataclean.

Thanks for your reply Tom and yes my mistake. I did get him to add a couple of bottles of Cataclean in a quarter tank of fuel running it almost dry, but unfortunately it didn’t do the trick. 

39 minutes ago, Hebridean said:

Thanks for your reply Tom and yes my mistake. I did get him to add a couple of bottles of Cataclean in a quarter tank of fuel running it almost dry, but unfortunately it didn’t do the trick. 

Ok, just try a generic exhaust shop for a quote on a new cat in that case.  Not a difficult job so shouldn't need a competent mechanic.

I would like the two cat sensors to be checked before committing to a new cat converter. Hence the request for a recommendation.

Fair enough, that's your choice.  It usually is the cat on the 1.0 EcoBoost though.  Changing the sensors often appears to fix it at first, but the code will come back within a few months.

If the O2 Sensors were faulty I would expect a Fault Code, but not a P420 one.