Method And System For Determining An Amount Of A Substance In Exhaust Gas Of An Internal Combustion Engine

The present invention refers to a method for determining an amount of a substance in exhaust gas of an internal combustion engine, the method comprises the steps of: determining, for an effective condition of the engine, at least one operating parameter; determining, for a reference condition of the engine, a reference amount of the substance present in exhaust gas of the engine in the reference condition when being operated based on the determined operating parameter; determining an intake manifold temperature difference between the effective condition and the reference condition of the engine; and determining an effective amount of the substance in the exhaust gas of the engine in the effective condition in dependence on the determined reference amount of the substance and the determined intake manifold temperature difference.