Method for monitoring exhaust gas aftertreatment system of an internal combustion engine, uses lambda map-based pilot control that provides constant increase of lambda value from minimum to maximum lambda value within acceptable range

摘要

The method involves determining the oxygen storage capacity of a catalyst (70) using a lambda map-based pilot control, where the lambda value lies between the rich and lean air fuel mixture ratios. The map-based pilot control also provides constant increase of the lambda value from minimum to maximum lambda value within an acceptable range. The constant increase of the lambda value is preferably in the form of a linear slope or ramp under servo-control. An independent claim is also included for a device for monitoring of an exhaust gas aftertreatment system of an IC engine.