Method and apparatus for operating a lean NOx trap

摘要

Disclosed is a method and apparatus for operating a lean NOx trap 20 in an Internal Combustion Engine 10 equipped with an Electronic Control Unit, ECU 22 the method comprising: determining a value of a parameter indicative of a NOx loading level in the lean NOx trap 20 and starting a regeneration event of the lean NOx trap 20, if the determined value of the parameter fulfils a predetermined activating criterion related to this parameter. The method may use a rolling average of the NOx trap efficiency to determine when regeneration is required.