Exhaust system for a motor vehicle and method for operating an exhaust system

Abstract

Exhaust system for a motor vehicle, with a discharge line (14) for the removal of exhaust gases originating from an internal combustion engine (12), an exhaust gas catalyst (16) connected to the discharge line (14) for converting pollutants from the exhaust gas, a drain (18) connected to the exhaust catalyst (16) for the discharge of the exhaust gases coming from the exhaust catalyst (16) to the environment, a bypass line (20) connected to the discharge line (14) and to the discharge line (18) and routed past the exhaust catalyst (16) to bypass the exhaust catalyst (16) and a locking element (24) provided downstream of the exhaust catalyst (16) in the line (18) for releasably closing a fluidic connection between the exhaust catalyst (16) and the line (18) and for increasing a back pressure in the exhaust catalyst (16) by exhaust gas introduced into the exhaust catalyst shortly before the start of a fuel cut-off and retained in the exhaust catalyst (16), wherein a control unit coupled to an engine control unit for the internal combustion engine (12) is provided for diverting exhaust gas into the bypass line (20) in the event of overrun shutdown of the internal combustion engine (12).