114 Driving and operatingStopping the journey or switching offthe engine during cleaning is notrecommended.CautionIf the cleaning process isinterrupted more than once, thereis a great risk of provoking severeengine damage.Cleaning takes place quickest at highengine speeds and loads.The control indicator ! extinguishesas soon as the self-cleaningoperation is complete.Catalytic converterThe catalytic converter reduces theamount of harmful substances in theexhaust gases.CautionFuel grades other than those listedon pages 3 127, 3 186 coulddamage the catalytic converter orelectronic components.Unburnt petrol will overheat anddamage the catalytic converter.Therefore avoid excessive use ofthe starter, running the fuel tankdry and starting the engine bypushing or towing.In the event of misfiring, unevenengine running, a reduction in engineperformance or other unusualproblems, have the cause of the faultrectified by a workshop as soon aspossible. In an emergency, drivingcan be continued for a short period,keeping vehicle speed and enginespeed low.
