FACTS About O2 sensors and why Heated Oxygen sensor??
[SIZE=3]Heated Oxygen Sensor (HO2S) [/SIZE][SIZE=3]Traditionally Oxygen sensor input has been used to calculate fuel trim when vehicle is in closed loop. Oxygen sensors still perform this function; however, to meet the emission regulations, GM uses oxygen sensors to almost monitor the catalyst.[/SIZE][SIZE=3]The emission regulations require that the vehicle enter closed loop sooner, as well. This because a vehicle that operates in close loop will produce less emissions than if it is operating in open loop. Unheated Oxygen Sensors may take longer to become activated. Therefore, they are slower to go into closed loop. HO2S are being used more frequently. The heater warms the sensor to help achieve activation temperature sooner allowing the system to enter and maintain closed loop status.[/SIZE]