Waste gas system for a combustion engine

The system has an exhaust gas cooler (2) including a channel (6) through which exhaust gas flows, where the exhaust gas cooler is bypassed through a bypass channel (24). A cooling agent flows through a cooling agent channel (8). The bypass channel is lockable by a bypass flap. An exhaust gas recirculation valve is arranged to the gas cooler and the bypass channel. A cooling agent valve (32) is arranged in the cooling agent channel for locking the agent channel. The agent valve is operated together with the bypass channel by an actively controlled actuator (28). An independent claim is also included for a method for cleaning an exhaust gas recirculation valve of a waste gas system.