How to Measure the Condition of an Oxygen Sensor?
2 Answers
Methods for measuring the condition of an oxygen sensor are as follows: 1. Check with a decoder: If the oxygen sensor malfunctions, the car's ECU will store a fault code. You can directly use a decoder to detect it. If a fault code appears on the machine, it indicates an oxygen sensor failure. 2. Check the resistance of the oxygen sensor heating element: Under normal conditions, the resistance of the oxygen sensor heating element is 1-5 ohms. Use a multimeter's resistance setting to measure the resistance between the two ends of the oxygen sensor wiring harness connector to determine if there is a malfunction. 3. Check the power supply of the oxygen sensor heating element: When using a multimeter to check the oxygen sensor heating element, start the engine and measure the power supply voltage at both ends of the oxygen sensor wiring harness connector. The normal voltage should be above 11V.
To test the oxygen sensor's condition, I usually start by using an onboard diagnostic tool to read the data stream, checking if the voltage fluctuates rapidly between 0.1 and 0.9 volts. A stable signal and quick response indicate normal operation; if the voltage is fixed or unchanging, it might be faulty. Next, I use a multimeter to measure the resistance—the heater's normal range is typically between 5 and 20 ohms, and values too high or too low indicate a problem. Don’t forget to inspect the wiring for corrosion or looseness, as these often cause false faults. A faulty oxygen sensor leads to incomplete engine combustion, spiking fuel consumption and polluting the environment, so replace it promptly if issues are detected to ensure the car remains energy-efficient and eco-friendly. Regular simple checks, like observing exhaust color or idle vibrations, can also alert you to potential risks, saving both hassle and fuel.
