checks vaccum leaks, spark plug problem, air mass problem, fuel injector and etc. possible software error in DME, might need software update. Depend, it have various factors. do the adaptation reset first which is the mixture reset and Valvetronic Lift reset. It will help and depend the condition of the issue. 21A02D Combustion Control Idle Regular, the vehicle will run rough or hesitate when accelerating from a stationary position. Thank you
