Förfarande och system för att kontrollera av utsläpp från en förbränningsmotor

摘要

The invention relates to a method for combustion engine pollution control. NOx value of the exhaust gases from the engine is measured (207) and the lambda value in the engine operation is controlled in response to the measured NOx value. In case where the measured NOx value is over the reference value a signal to decrease the NOx emissions by way of increasing the lambda value through a waste-gate control device (28) is outputted by a NOx control (23). An ignition timing offset signal for retarding ignition timing is outputted (202) to an ignition timing control function (25) by the NOx control (23), if the waste-gate control device (28) is unable to lower the NOx value to a targeted NOx level.