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Check the Signal waveform of HO2S

IG "OFF" and connect HO2S connector.
Engine start.
After warming-up, monitor signal waveform of HO2S with scantool.

Fig 1: Identifying Signal Waveform
Courtesy of HYUNDAI MOTOR CO.
Is the sensor switching properly?
YES
- Go to "CHECK HO2S " as below.
NO
- Substitute with a known - good HO2S and check for proper operation. If the problem is corrected, go to "VERIFICATION OF VEHICLE REPAIR " procedure.