Theory Of Operation
WARNING: This page is about a different car, the 2013 RAM 3500 HD and 2013 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
The Downstream O2 Sensor, located in the exhaust path behind the Catalytic Converter, is monitored for proper response to assure optimum Catalytic Converter efficiency. The Downstream O2 Sensor response monitor is intended to diagnose a Downstream O2 Sensor that is not moving or stuck in a voltage window and to insure accurate information for catalyst monitor diagnosis.