How to Replace the Oxygen Sensor in a Jettaby Dan Ferrell
Replacing the oxygen (O2S) sensor on your Volkswagen Jetta is a simple process. Wear long sleeves and working gloves if necessary to prevent skin burns, and then follow these steps to remove and install the new sensor in your Jetta. You can buy these sensors at most auto parts stores.
Locate the Oxygen Sensors
Warm up the engine to operating temperature. In most cases, you need to warm up the engine to ease the threads--on the sensor mounting bolts or the sensor itself--off the exhaust manifold or pipe. Trying to force loose a hard-to-remove sensor with the exhaust system bellow 120 degrees F (48 C) may damage the threads and result in costly repairs.
Open the hood and locate the oxygen sensor or sensors you want to replace. The sensor has a cylindrical body and is the size of a spark plug. Depending on your particular model, you may find the sensor mounted on the exhaust manifold or the exhaust pipe connected to the manifold. The upstream sensor is located right before the catalytic converter and the downstream sensor right after the catalytic converter.
Disconnect the black, negative battery cable.
Raise the front of the vehicle using a floor jack and safely support it on two jack stands if necessary.
Remove the Old Oxygen Sensor
Unplug the sensor's electrical connector from its harness.
Unscrew the two mounting bolts using a wrench or ratchet and socket, if you have a flange-type sensor. If you have a screw-in type sensor, remove it with a box-end wrench or a ratchet and oxygen sensor socket.
Remove the oxygen sensor gasket from the exhaust pipe mounting base if you have a flange-type sensor.
Remove the sensor from the vehicle.
Install a New Oxygen Sensor
Apply a light coat of anti-seize compound to the threads of the two sensor mounting bolts if you have the flange type or to the threads on the body of the sensor if you have the screw-in type. Make sure the compound does not get to the tip of the sensor.
Set the new sensor in place and new gasket if required.
Start the two mounting bolts by hand if you have the flange-type sensor, or screw the sensor in place by hand, if you have the screw-in type.
Tighten the mounting bolts or the sensor to the exhaust pipe.
Plug the sensor electrical connector.
Remove and install the other sensor, if necessary, following the steps on the last two sections.
Lower the vehicle.
Connect the black, negative battery cable.
- On some Jetta models, you may need to remove the passenger seat and the carpeting to access the downstream oxygen sensor electrical connector.
Things You'll Need
- Floor jack and 2 jack stands
- Wrench set
- Ratchet and socket
- Box-end wrench or oxygen sensor socket
- Anti-seize compound
- Oxygen sensor gasket if required
Since 2003 Dan Ferrell has contributed general and consumer-oriented news to television and the Web. His work has appeared in Texas, New Mexico and Miami and on various websites. Ferrell is a certified automation and control technician from the Advanced Technology Center in El Paso, Texas.