Good morning After my knowledge, the control units in our vehicles check driving cycles. On the one hand, I read what of 3 driving cycles in a row. So start, drive, set off and then 40 hot cycles. I understand this way: Is there an error message in the system which 40 driving cycles will no longer appear later, the error will be automatically deleted. In the exhaust system such a reading code is probably generated. So the system checks itself again and again whether the exhaust-relevant parts run. Correct?? To the topic NOX sensor (All other errors are excluded) Can the following procedure be FALSCH: 1. Error read out P20ee 2. Error deleted! 3.Taush of the NOX sensor result: new NOX sensor does not provide a measurement value! Can it be that the exhaust system first has to generate a new reading code / driving cycles until the NEW NOx sensor is recognized as active and delivers values?