Oxygen Sensor
Oxygen sensor used in DFI system is a closed end Zirconia sensor placed in exhaust gas stream. This sensor produces a very weak voltage which varies with oxygen content of exhaust gases. As oxygen content of exhaust gases increases, a leaner mixture is indicated by low voltage output. As oxygen content decreases, a richer mixture is indicated by higher voltage output. The ECM corrects air/fuel ratio according to signals received from oxygen sensor.
NOTE:
No attempt should be made to measure oxygen sensor voltage output. Current drain of conventional voltmeter could permanently damage sensor, shift sensor calibration range and/or render sensor unusable. Do not connect jumper wire, test leads or other electrical connectors to sensor.