A method for treating a flow of exhaust from an engine includes injecting reductant into the flow of exhaust with an injector disposed upstream from a catalytic device. The injector and the catalytic device are disposed in an exhaust system for the engine. The method also includes passing the flow of exhaust through the catalytic device, sensing a characteristic of at least one of the exhaust system and the engine, monitoring the sensed characteristic to recognize a condition associated with a formation of a decomposition material formed from the reductant, and controlling an operation of at least one of the engine and the exhaust system to increase a temperature in the exhaust system in response to the recognized condition.