What is the normal voltage range for an oxygen sensor?
2 Answers
The normal voltage range for an oxygen sensor is between 0.1-0.9V, with an average value typically between 0.4-0.5V. Here is more information about oxygen sensors: 1. The faster the voltage frequency changes of the oxygen sensor, the better the sensor's performance. 2. If the voltage reads 0V or 1V, or remains unchanged, it indicates that the oxygen sensor has severely aged and needs immediate replacement. 3. The normal voltage differs between the front and rear oxygen sensors, with the front sensor's signal typically higher than the rear sensor's under normal conditions. 4. If the oxygen concentration data obtained from both the front and rear oxygen sensors are identical, it suggests that the three-way catalytic converter has failed.
Last time when I got my car repaired, the mechanic explained that the oxygen sensor voltage should fluctuate between 0.1-0.9V to be considered healthy. Specifically, at idle speed, the voltage slightly fluctuates around 0.45V. When you step on the gas pedal and the mixture becomes richer, the voltage can surge to 0.9V, and it immediately drops to 0.1V when you release the throttle. Remember, it's normal for the voltage to be low during a cold start; the sensor only starts working when the exhaust pipe temperature reaches 300 degrees. By the way, during testing, if the voltage is stuck at 0.45V without any movement, it could mean the sensor is clogged with carbon deposits or the wiring harness is melted. If this part fails, fuel consumption will skyrocket, and the exhaust will smell like rotten eggs, so it's better to replace it as soon as possible.
