Component Inspection

Visually/physically inspect following items:
- 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 "FR OXYGEN SNSR-B1" parameter on the Scan Tool data list.
Specification: Verify signal is switching from rich (above 0.45V) to lean (below 0.45V) a minimum of 3 times in 10 seconds (voltage will vary between 0.1 and 0.9V).

Fig 1: Connecting Scan Tool And Monitoring "FR OXYGEN SNSR-B1" Parameter On Scan Tool Data List
Courtesy of HYUNDAI MOTOR CO.
Is sensor switching properly?
YES:
- Check for poor connection between ECM 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.