What does an oxygen sensor voltage reading of 0.4 - 0.5V suggest?

An oxygen sensor voltage reading of 0.4 - 0.5V indicates a normal fuel mixture, suggesting that the air-fuel ratio is within an acceptable range for efficient combustion. The voltage signal from the oxygen sensor fluctuates based on the oxygen content in the exhaust gases. Typically, a reading around this range reflects a balanced combustion process, where enough fuel is present to produce optimal power without generating excessive emissions, indicating that the engine management system is properly regulating the mixture.

In contrast, readings significantly above 0.5V usually signify a rich fuel mixture, while readings below this threshold would suggest a lean condition. A faulty air-fuel mixture error would typically manifest with erratic voltage readings outside of the expected range. Understanding these voltage readings is crucial for diagnosing fuel mixture issues and ensuring the vehicle operates efficiently while complying with emissions standards.