Patent ID: 8190352

Claim:
A method for diagnosing an exhaust gas catalytic converter, comprising the steps of: detecting a first exhaust gas sensor signal of a first exhaust gas sensor which is arranged in an exhaust gas tract upstream of the exhaust gas catalytic converter, detecting a second exhaust gas sensor signal of a second exhaust gas sensor which is arranged in the exhaust gas tract downstream of the exhaust gas catalytic converter, determining a relevant first estimated value of an emission of at least one exhaust gas component in relation to a position of the first exhaust gas sensor in the exhaust gas tract as a function of the first exhaust gas sensor signal, determining a relevant second estimated value of an emission of the at least one gas component in relation to a position of the second exhaust gas sensor in the exhaust gas tract as a relation to the second exhaust gas sensor signal, estimating a conversion rate of the at least one exhaust gas component as a function of a relation between the second estimated value and the first estimated value of the determined emission, and diagnosing the exhaust gas catalytic converter as a function of the determined conversion rate.