Component Inspection

Visually/physically inspect following items:
- Visually/physically inspect the front HO2S for contamination, deterioration, or damage.
- Inspect the front HO2S for any silicon contamination. This contamination will be indicated by a white powdery coating and this will result in a but false voltage signal.
- If contamination is evident on the HO2S, replace contaminated sensor and go to next step.
Warm up the engine to normal operating temperature and check that HO2S signal is active.
Connect scan tool and monitor the "O2 SNSR VOLT.(B1/S1)" parameter on the scan tool data list.
Test Condition : Engine "ON" and In Closed loop mode.

Fig 1: Scan Tool Display - O2 SENSOR VOLTAGE
Courtesy of KIA MOTORS AMERICA, INC.
Is sensor data near the specified value?
YES
- Check for poor connection between PCM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection. Repair as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
NO
- Check HO2S for contamination, deterioration, or damage. Substitute with a known-good HO2S and check for proper operation. If the problem is corrected, replace HO2S and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.