Systems and methods for controlling a valve for directing an exhaust gas stream through an exhaust duct having a first after treatment device and a second after treatment device in an exhaust system. The method includes receiving sensor signals from a sensor coupled to the second after treatment device. The method includes processing the sensor signals to determine a temperature of the second after treatment device, and determining a position for the valve based on whether the temperature exceeds a pre-defined threshold for the temperature of the second after treatment device. The method includes outputting a control signal to move the valve to a first position in which the exhaust gas stream flows through a first portion of the first after treatment device or a second position in which the exhaust gas stream flows through a second portion of the first after treatment device based on the temperature.