How to Replace Oxygen Sensor
You are supposed to replace theoxygen sensorat regular intervals. How often? That depends on the type of sensor installed in your car. In general, you should install a new, regular oxygen (02) sensor-equipped with one or two wires-after 50,000 miles of operation, and a heated oxygen sensor-equipped with three or more wires-after reaching the 100,000 miles. With age, the sensor becomes dirty or coated with exhaust byproducts, affecting its capacity to measure oxygen content in the exhaust stream. Then, emissions and fuel consumption increase. Fortunately, you can do this repair job in your own driveway in about an hour.Automotive oxygen sensor removalIt is a good idea to spray penetrating oil around the base of the oxygen sensor the night before you plan to remove it. O2 sensors have a tendency to get stuck on the exhaust pipe where they are mounted. Penetrating oil will make your job easier. When you are ready, disconnect the black battery cable and isolate it by wrapping a rag around the terminal to prevent it from accidentally touching the battery post. Then, lift the front of your vehicle, if the sensor you are replacing is located near the catalytic converter, to gain better access to the sensor.Unplug the sensorelectrical connector. Use an oxygen sensor socket and a ratchet to unscrew the unit from the exhaust pipe. If you feel the sensor is hard to remove, don’t force it. Instead, block the rear wheels of your vehicle, set your transmission to Neutral (standard) or Park (automatic) and start the engine. Let the engine idle for about 10 minutes. This will allow the O2 sensor temperature to rise above 120 F (49 C) and make it easier to remove. If you try to force a stuck sensor, you may damage the threads on the exhaust pipe and end up with a very expensive job repair.Installing the new oxygen sensorWhen handling the new sensor replacement, avoid touching the tip and keep it away from oil, grease, coolant and other substances during your installation process. These and other substances may cut short its service life. Carefully, before you install it, coat the threads of the new unit with anti-seize compound. This will help prevent the threads from seizing onto the exhaust pipe and damage. Then, install the sensor by hand and tighten it with the socket and ratchet, but do not over tighten it. Plug in the sensor electrical connector, lower the vehicle, if necessary, and reconnect the battery.When an oxygensensor becomes faulty, the car’s computer will alert you by turning on the check engine light or malfunction indicator light (MIL) and store a trouble code in memory. You will need to erase this code from memory using a code reader or scan tool and reset the check engine light. If you don’t have access to a code reader or scan tool, you might be able to take your car to an auto parts store where they may offer this service free of charge.
