Method for Determining the Oxygen Load of a Catalytic Converter of an Internal Combustion Engine, and Exhaust System of an Internal Combustion Engine

Various embodiments include a method of ascertaining the oxygen load of a catalytic converter disposed in an exhaust tract of an internal combustion engine with an exhaust gas sensor is disposed downstream of the catalytic converter comprising: generating a signal using the exhaust gas sensor indicating a proportion of nitrogen oxide and/or ammonia in the exhaust gas; and ascertaining the oxygen load of the catalytic converter at least partly on the basis of the signal from the exhaust gas sensor.