Sub Oxygen Sensor OX

The sub-oxygen sensor is used on California and some Federal engines. It is used to monitor the exhaust stream after the catalyst to determine if the air/fuel mixture is within the range for efficient converter operation.

Exhaust Manifold

Exhaust Manifold

The sub-oxygen sensor is identical to the Zr02 main oxygen sensor located ahead of the catalyst. Information from this sensor is used by the ECU to fine tune the air/fuel ratio and improve emissions.

Oxygen Sensor Terminal Identification


Main Oxygen Sensor

Analog signal representing pre-catalyst exhaust oxygen content


Sub-Oxygen Sensor

Analog signal representing post-catalyst exhaust oxygen content


Oxygen Sensor Signal

Titania Oxygen Sensor Analog Signal


Oxygen Sensor Reference

Titania Oxygen Sensor Reference Voltage


Oxygen Sensor Heater

Sensor heater current path


Earth Ground

Sensor ground return path

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  • marko
    Where is sub oxygen sensor on 95 toyota corolla with California emissions?
    3 years ago
  • abbie
    How to rectify sub oxygen sensor signal?
    2 years ago
  • anneli
    What is a main and sub o2 sensor?
    1 year ago
  • stanley
    Can i disconnect sub oxygen sensor on 89 t0yota 5sfe?
    1 year ago
  • mary
    What is sub 02 sensos?
    1 month ago

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