What could a constant low voltage reading of around 0.2 volts from the front oxygen sensor during a catalytic converter test indicate?

A constant low voltage reading of around 0.2 volts from the front oxygen sensor during a catalytic converter test suggests that the sensor is detecting a very lean air-fuel mixture. This scenario may indicate that there is an issue with the airflow measurement, which could involve a malfunctioning Mass Air Flow (MAF) sensor. The MAF sensor plays a critical role in determining the amount of air entering the engine, and if it isn't working properly, it can lead to incorrect fuel management, resulting in improper combustion and subsequently low voltage readings from the oxygen sensor.

In this specific case, the oxygen sensor is expected to produce varying voltage readings based on changing conditions in the exhaust system; low and stable voltage points toward a lack of response to changes in the air-fuel mixture, further implying that the MAF sensor may not be reporting the correct data to the engine control module. This creates a scenario where the engine runs with incorrect air-fuel ratios, affecting overall performance and emissions.

The other conditions listed, such as a faulty fuel pump, a blocked air filter, or an exhaust gas leak, would present different symptoms and voltage readings, not specifically the low and constant values seen here. Each of those issues typically results in different problems related to fuel