Process and device for diagnosing a NOx-catalyst-absorber in a stationery vehicle

摘要

Process for diagnosing a NOx storage catalyst arranged in an exhaust gas channel of an I. C. engine comprises, when the vehicle is stationary, adjusting the catalyst temperature to a value in a region representing NOx storage, adjusting a NOx reference state of the storage catalyst to measure NOx lean conversion, impinging the catalyst with exhaust gas having a NOX mass stream greater than the theoretical value, carrying out a lean operating phase, measuring an exhaust gas characteristic parameter for NOx conversion using a sensor arranged downstream of the catalyst, determining the condition of the catalyst depending on the measuring values of the exhaust gas characteristic parameter, and outputting the condition value of via a diagnostic interface. An Independent claim is also included for a device for diagnosing a NOx storage catalyst arranged in an exhaust gas channel of an I. C. engine.