HO2S Heater

Heated oxygen sensors are used in order to minimize the amount of time required for a closed loop fuel control operation and in order to allow accurate catalyst monitoring. The oxygen sensor heater greatly decreases the amount of time required for fuel control sensors Bank 1 HO2S 1 and Bank 2 HO2S 1 to become active. The oxygen sensor heaters are required by catalyst monitor sensors Bank 1 HO2S 2 and Bank 1 HO2S 3 to maintain a sufficiently high temperature which allows accurate exhaust oxygen content readings further from the engine.