Signal Waveform & Data

Fig 1: Normal Waveforms Of Upstream HO2S (Upper) & Downstream HO2S (Lower) With Chassis Ground Used

Courtesy of HYUNDAI MOTOR AMERICA

Fig 2: Normal Waveforms Of Upstream HO2S (Upper) & Downstream HO2S (Lower) With Sensor Ground Used

Courtesy of HYUNDAI MOTOR AMERICA

Fig 3: Normal Graph Of Upstream HO2S & Downstream HO2S At Idle

Courtesy of HYUNDAI MOTOR AMERICA

After warming-up, if accelerator pedal is released suddenly around 4000 rpm, the HO2S signal reading will be lower than 200 mV resulting from fuel cut-off for the moment. Conversely, if accelerator pedal is suddenly depressed, HO2S signal reading will be around 0.6V ~1.0V. At idle, normal HO2S signal will switch from lean to rich at 3 Hz. With higher engine RPM the signal frequency will increase.