method for the regeneration of an exhaust system of an internal combustion engine in stickoxidfalle

摘要

A nitrogen oxide (NOX) trap is regenerated immediately before reducing the fuel injection amount for lean mixture operation. In a NOX trap regeneration method, in which a regeneration cycle is initiated or terminated by varying the fuel injection amount, the NOX trap is regenerated immediately before reduction in the fuel injection amount for lean mixture operation. Preferred Features: The regeneration cycle duration is varied as a function of the oxygen storage capacity of the catalytic converter and/or the storage capacity of the NOX trap, these capacities being adapted according to a model concerning duration of engine operation, vehicle mileage, catalytic converter operating conditions and / or NOX trap operating conditions. The air / fuel ratio, required for NOX trap regeneration, is dependent on the exhaust gas temperature near the NOX trap and the exhaust gas mass flow.