My light came on last Sunday! I noticed a loss of power, so I took it to the dealership as it's still under warranty and advised me that the O2 (Hego) sensor was faulty.

They advised the Mountune upgrade was partly to blame!! I thought their comments were a load of c**p! Why would Mountune fit Ford approved upgrades to this vehicle!?!

Anyway all sorted and was completed as a goodwill gesture due to not being covered under warranty. This part is only covered within the first 12 months.

Finally, all Manchester owners don't take your ST to Ford at Sretford, Old Trafford as they dont have a clue what they're talking about.