The specific methods for detecting the quality of oxygen sensor are:
1. You can distinguish the quality of oxygen sensor by observing the color of the top part of oxygen sensor. Light gray top: normal color of oxygen sensor. White top: caused by silicon pollution, oxygen sensor must be replaced at this time. Brown top: caused by lead pollution, if serious, oxygen sensor must also be replaced. Black top: caused by carbon deposits, after eliminating the engine carbon deposit fault, the carbon deposits on oxygen sensor can generally be automatically removed.
2. Detect sensor resistance. You can use a multimeter to check the resistance of oxygen sensor (between heater terminal and grounding terminal), which is generally 4 to 40 ohms.
3. Measure the change of oxygen sensor voltage output signal. The output voltage of oxygen sensor is generally between 0.2 and 0.9V, and its change range is about 0.5V, indicating that the sensor performance is good.
4. Lighter burning method. The flame of the lighter consumes the oxygen in the head of oxygen sensor, the oxygen content decreases, and the output voltage of oxygen sensor increases. If it is turned off, the oxygen content increases, the output voltage of oxygen sensor decreases, and the reading of multimeter can be used to determine whether the oxygen sensor is working properly. The output voltage of the oxygen sensor is generally between 0.1V and 0.9V. If the output voltage exceeds this range, it also indicates that the oxygen sensor is damaged.
5. Use a car computer tester to judge. It is necessary to preheat the car before driving. When the water temperature reaches 80 degrees, check the voltage value of the oxygen sensor of the computer tester. It will change from 0V to 1V continuously. The faster the frequency, the better the sensor. If the voltage is 0v or 1v, or there is no change, it means that the sensor is aging or working poorly and needs to be replaced.