Signal Waveform & Data

Fig 1: Scantool Display - Normal Waveforms Of Front HO2S (Upper) & Rear HO2S (Lower)

Courtesy of HYUNDAI MOTOR CO.

Fig 2: Scantool Display - Normal Graph Of Front HO2S & Rear HO2S At Idle

Courtesy of HYUNDAI MOTOR CO.

After warming-up, if accelerator pedal is released suddenly around 4000 RPM, the HO2S signal reading will be lower than 200mV. This will result in momentary fuel cut-off. On the contrary, if the accelerator pedal is suddenly depressed, the HO2S signal reading will be around 0.6V ~1.0V. At idle, the HO2S signal will normally switch from lean to rich with 3 Hz, and when engine RPM is increasing, its frequency will rise.