Upstream (S1) Heated Oxygen Sensor (HO2S) Visual Inspection
- Ignition "OFF" and disconnect HO2S (S1) connector.
- Check that HO2S (S1) is not contaminated or damaged by foreign materials.
YES
- Go to "PCSV Inspection " procedure below.
NO
- Replace it, and go to "Verification of Vehicle Repair " procedure.