HO2S Heater

The Heated oxygen sensor (HO2S) is used to minimize the amount of time required for closed loop fuel control operation and 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. 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.