FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.

H14 - Check HO2S Integrity




Heated Oxygen Sensor (HO2S) always lean, slow to switch or lack of switching. Fuel at adaptive limit could be caused by:

- Moisture inside the HO2S harness connector resulting in a short to ground.

- HO2S coated with contaminants.

- HO2S circuit open.

- HO2S circuit shorted to ground.

- Key "OFF".

- Inspect the HO2S harness for chafing, burns or other indications of damage. Service as necessary.

- Inspect HO2S and connector for indication of submerging in water, oil, coolant, etc. Service as necessary.

- Run engine at 2000 rpm for two minutes.

- Key "OFF".

- Run Engine Running Self-Test. Key ON Engine Running (KOER) Self-Test

- Are fault codes present?

Yes -- Go to H16. H16 - Check HO2S On Engines With MAF Sensor

No -- Go to H21. H21 - Check Resistance of Heated Element On HO2S