About GM Oxygen Sensor
The role of the oxygen sensor is to effectively control fuel emissions for better engine performance and fuel economy. It analyzes the exhaust fumes and deposits produced by the engine to gather data of the air-fuel ratio. If the ratio is off, the sensor sends feedback to the vehicle's engine control system so the fuel mixture can be adjusted accordingly. Common signs of a faulty GM oxygen sensor are unstable idling speeds and a sudden drop in gas mileage.