If an oxygen sensor voltage range is 0.6 - 1.0V, what does it signify?

An oxygen sensor reading within a voltage range of 0.6 to 1.0 volts indicates a rich fuel mixture. In this scenario, the oxygen sensor is detecting a higher concentration of fuel in relation to the amount of air present in the exhaust gases. When the voltage is elevated, it typically suggests that there is insufficient oxygen to fully combust the fuel, leading to a richer mix.

In contrast, a normal fuel mixture would generally produce a voltage reading closer to 0.45 volts, while a lean fuel mixture would be represented by a lower voltage, typically below 0.5 volts. Additionally, a faulty oxygen sensor might provide erratic readings or stay at a constant value that does not correspond with the actual air-fuel mixture, indicating a malfunction in the sensor itself rather than a specific mixture condition. Thus, understanding the significance of these voltage ranges is crucial for diagnosing air-fuel mixture issues in an engine's operation.