Question

When volt checking an O₂ sensor, what is considered a good reading?

1) 0.1-0.3 volts
2) 0.3-0.5 volts
3) 0.5-0.7 volts
4) 1.0-1.5 volts

Answer 1

The correct option is 0.5-0.7 volts.

A good reading when volt checking an O2 sensor is typically between 0.5-0.7 volts. The sensor should fluctuate between 0.1 and 0.9 volts, responding to oxygen content changes in the exhaust. Always check the vehicle's manual for model-specific voltage ranges.

Step-by-step explanation:

When performing a volt check on an O2 sensor, which is also known as an oxygen sensor, a good reading would typically be between 0.5-0.7 volts. The O2 sensor measures the oxygen content in the exhaust gases and sends this data to the vehicle's computer system. A sensor in good condition should fluctuate steadily between 0.1 volts (lean mixture) and 0.9 volts (rich mixture) as it responds to changes in the oxygen content detected in the exhaust.

However, a constant reading in the midrange, such as 0.45 volts which falls between the 0.3-0.5 volts range, might also indicate a properly functioning sensor under certain steady state conditions. It's essential to consult the vehicle's service manual for the specific voltage range expected for a healthy O2 sensor on that particular model, as this can vary.