Patent ID: 8074447

Claim:
A method of determining sulfur removal of a NO x catalytic converter in an exhaust gas aftertreatment system of an internal combustion engine, the method comprising: adjusting conditions in which a reducing agent surplus is generated for the sulfur removal; and determining an SO x removal amount in an SO x removal calculation using a model from a reducing agent flow and from additional operational parameters of the internal combustion engine, wherein the reducing agent flow is determined during sulfur removal from a reducing agent characteristic diagram that is constructed from an operating state, a rotational speed, and a torque of the internal combustion engine, wherein the reducing agent flow is corrected with a Lambda correction calculated from a deviation from a set point Lambda value and an actual Lambda value, and wherein the corrected reducing agent flow is integrated and when a specifiable reducing agent threshold value is achieved, the operating conditions for the generation of the reducing agent flow in the exhaust gas are terminated according to a specifiable time.