Mini Countryman R60 starts with engine control light, jerks and stutters and goes into emergency run

Hello to each other We drive an 8 year old Mini R60 with 1.6 engine from the house PSA – this one has been in emergency run for a time and jerks while driving! Engine lamp lights constantly. We would have had the light from time to time and it also went over but that is not anymore. Was also with BMW which also took care of him checkbook but with a diagnosis the friendly everything was in order – error memory deleted lamp was gone but the problem came back. Z Ündkerzen are new now but that brought so far nothing! If it were the Lambda probe that would be in the diagnosis or?! After a long drive the emergency run goes out again and full power is given however then under pressure the sporadic stuttering comes back! Have already added a petrol system cleaning of Liqui Moly and tank now also some better petrol. Do you have hints or tips?! Thank you in advance!