Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la
If it fails: lemon-manuals.org.ua

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Oxygen Sensor: Testing and Inspection

HEATED OXYGEN SENSOR (HO2S)

NOTE: Both sensors are identical. Inspect each in the same way.

1. Inspect the pigtail and the electrical connector for grease, dirt, corrosion and bare wire or worn insulation.




2. Inspect the louvered end of the sensor for grease, dirt, excessive carbon build up or other contaminants.