Visually/physically inspect the following items:

-Vacuum hoses for splits, kinks and improper connections.

-Exhaust system between HO2S and Three way catalyst for air leakage

-EVAP system for leakage

-PCV hose for proper installation

Was a problem found in any of the above areas?

YES

▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure

NO

▶ Go to next step as below

Visually/physically inspect the following items:

-Check for corrosion on terminals

-Check for terminal tension ( at the HO2S and at the ECM)

-Check for damaged wiring

-Check the HO2S ground circuit for a good connection

-Check front and rear HO2S for connections being reversed.

Was a problem found in any of the above areas?

YES

▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure

NO

▶ Go to next step as below