In a method for monitoring an exhaust gas limiting value of an internal combustion engine using an engine controller, the engine controller has at least one exhaust gas sensor, and an error signal is output when the exhaust gas limiting value is exceeded. If the emissions predicted for the present driving state are ascertained with the aid of an engine model and compared to the signal of the exhaust gas sensor or a comparison value for the emission derived therefrom, the prescribed driving cycle may be taken into account when certifying a limiting value monitoring system and a defective system may be reliably recognized in practical operation even in atypical driving states without resulting in erroneous triggering of error signals.