Check HO2S

WARNING: This page is about a different car, the 2021 Hyundai Kona. However, it is still accessible from the selected car via links, so may be relevant.

Visually/physically inspect the following parts:
- Ensure that the HO2S is securely installed.
- Silicon contamination; This contamination will be indication by the white powdery coating on the portion of the sensor exposed to the exhaust stream and this will result in a but false (high) voltage signal
- Fuel, engine coolant or oil contamination
- Use of improper sealant
- If contamination is evident on the HO2S, fix the source of the sensor contamination before replacing the sensor to prevent future contamination. Go to VERIFICATION OF REPAIR procedure.
Warm up the engine to normal operating temperature and let it idle.
Connect GDS and monitor the O2 SNSR VOL. - B1/S1 parameter on the GDS 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) at idle. (Refer to "SIGNAL WAVEFORM & DATA.)
Is sensor switching properly?
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 REPAIR procedure.
NO
- Check HO2S for contamination, deterioration, or damage. Substitute with known-good HO2S and check for proper operation. If the problem is corrected, replace HO2S and then go to VERIFICATION OF REPAIR procedure.