Method and device for equivalent adjustment of cylinder banks for motor system having internal combustion engine with plurality of cylinder banks

The invention relates to a method for operating a motor system having an internal combustion engine, which has cylinders in a plurality of cylinder groups, to which a fuel quantity can be supplied individually and to which the combustion exhaust gas of the cylinder groups is discharged into a common exhaust gas outlet via an exhaust gas junction by means of a respective exhaust gas line, the method has the following steps: determining a fuel quantity to be injected for the cylinders of each of the cylinder groups by means of a lambda control on the basis of a total exhaust gas-lambda value of the combustion exhaust gas determined by means of a total exhaust gas-lambda detector in the exhaust gas outlet; in order to compensate for different air-fuel ratios in the cylinder groups, an equivalent adjustment is carried out in accordance with at least one exhaust line-lambda value of the combustion exhaust gas in each of the exhaust lines associated with the cylinder groups, a compensation variable is provided for