How to Connect a Four-Wire Oxygen Sensor?

[DeWeston]

The four wires of the oxygen sensor are divided into two types: heater wires and signal wires. The heater wires refer to the power supply and ground wires of the heating coil, both of which are connected to the engine's computer, allowing the car's oxygen sensor to enter the working state more quickly. The other two signal wires are connected to the vehicle's power supply, playing a role in controlling the air-fuel ratio of the car, thereby improving the quality of fuel combustion in the car's engine. More details are as follows: 1. The oxygen sensor is installed in front of and behind the three-way catalytic converter. The oxygen sensor in front is called the front oxygen sensor, and the one behind is called the rear oxygen sensor. 2. The main function of the front oxygen sensor is to detect the oxygen content in the exhaust, and the ECU can adjust the air-fuel ratio based on the data transmitted by the front oxygen sensor. The main function of the rear oxygen sensor is to detect whether the three-way catalytic converter has failed.