Method and device for cleaning an exhaust gas flow of an exhaust gas turbocharged combustion engine

The method involves discharging a branch line in a bypass line upstream to a reactor (9) and/or a mixing point (10) for a reducing agent precursor e.g. urea. A branched exhaust gas flow (6''') is controlled or regulated by a control and/or regulating device based on an operating condition e.g. idle state and light load operation, of an internal combustion engine (1) and/or a threshold e.g. temperature threshold, at the reactor and/or before or after an exhaust gas turbine (3). The branched exhaust gas flow is branched from a main exhaust gas flow (6') and supplied to the bypass line. An independent claim is also included for a device for cleaning an exhaust gas flow of an exhaust gas turbocharged internal combustion engine.