Method and device for diagnosing and for calibrating an exhaust gas sensor

An exhaust gas system for an internal combustion engine, comprising:

• a control device, a first exhaust gas path and a second exhaust gas path, wherein the first exhaust gas path has at least one exhaust gas post treatment element, the exhaust gas post treatment output of which is reduced relative to an exhaust gas post treatment output of an exhaust gas post treatment element, wherein the first exhaust gas path and the second exhaust gas path are provided with at least one exhaust gas sensor arranged in an exhaust gas flow direction after an exhaust gas post treatment element for the exhaust gas that is generated by the internal combustion engine, wherein the control device is configured to determine pollutant values of a first part of the exhaust gas flow of the exhaust gas mass flow generated by the internal combustion engine measured by at least one exhaust gas sensor of the first exhaust gas path, and to compare them to values of the pollutants of a second part of an exhaust gas mass flow generated by the internal combustion engine determined by an exhaust gas sensor of the second exhaust gas path, and to issue at least one proportionality factor for proportionality between the values of the pollutants determined by the at least one exhaust gas sensor of the first exhaust gas path and the at least one exhaust gas sensor of the second exhaust gas path, and to issue, based on a matching of the values to a predetermined diagnostic value, a diagnosis of the exhaust gas system with the at least one proportionality factor,
• wherein the first exhaust gas path and the second exhaust gas path are configured for the exhaust gas mass flow to be divided and a volumetric flow conducted through the first exhaust gas path is smaller than the volumetric flow conducted through the second exhaust gas path.

A system, for diagnosing and calibrating an exhaust gas sensor comprising:

• one or more non-transitory computer readable medium;
• and
• at least one processor communicatively coupled to the one or more non-transitory computer readable medium, the processor operable:
• to read out measured values determined by respective exhaust gas sensors of an exhaust gas system, and to compare the measured values determined by at least one exhaust sensor of a first exhaust gas path to the measured values determined by at least one exhaust gas sensor of a second exhaust gas path, and to calculate at least one proportionality factor based on the comparison, and to issue an error message when the at least one proportionality factor deviates by an amount of a specified limiting value which is greater than a predetermined threshold value,
• wherein an exhaust gas mass flow is divided and a volumetric flow conducted through the first exhaust gas path is smaller than the volumetric flow conducted through the second exhaust gas path.