The invention relates to a method for operating a nitrogen oxide (NOx) storage
catalytic converter (12). During a first operating phase of the
storage catalytic converter (12), nitrogen oxides are stored and,
during a second operating phase, stored nitrogen oxides are discharged from the
converter (12). The stored quantity of nitrogen oxides is determined
during the first operating phase. In order to be able to determine start and end
of the second operating phase as accurately as possible, a quantity, which characterizes
the discharge quantity of nitrogen oxides, is determined during the second operating
phase and compared to the stored quantity of nitrogen oxides determined during
the first operating phase. With the comparison, a plausibility check and a calibration
of the output signal of a nitrogen oxide (NOx) sensor (14) can take
place. The nitrogen oxide (NOx) sensor (14) is disposed downstream
of the storage catalytic converter (12).
