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

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Oxygen Sensor: Service and Repair

Primary HO2S Replacement

Special Tools Required
O2 sensor wrench, Snap-on YA8875, SP Tools 93750 or equivalent, commercially available




1. Disconnect the primary HO2S 4P connector (A), then remove the primary HO2S (B).
2. Install the primary HO2S in the reverse order of removal.

Secondary HO2S Replacement

Special Tools Required
O2 sensor wrench, Snap-on YA8875, SP Tools 93750, or equivalent, commercially available




1. Disconnect the secondary HO2S 4P connector (A), then remove the secondary HO2S (B).
2. Install the secondary HO2S in the reverse order of removal.