Oxygen (O2) Sensor

O2 sensor (XJS equipped with 2) is mounted in the front converter or the exhaust down pipes, and monitors oxygen content in exhaust gases. Sensor generates voltage according to oxygen content and sends information to ECU. Voltage will vary from .1 volt (lean condition) to as high as one volt (rich condition).

Sensor will not generate voltage signal until it has reached operating temperature. ECU adjusts air/fuel ratio according to voltage signals received from sensor to obtain correct emissions. Until sensor reaches operating temperature, ECU adjusts air/fuel ratio based on preprogrammed information in ECU memory.