Replacing the oxygen sensors on your Nissan Pathfinder requires a special socket designed to remove and install the sensors. The oxygen sensors are a critical part of the engine management system and the car's computer depends on the reading from them to determine whether the engine is running rich or lean. The oxygen sensors can be purchased from the dealership if you want OEM parts, or they are also available from any auto parts store as aftermarket replacement parts.
Things You'll Need
- Jack stands
- Oxygen sensor socket
Raise the front of the truck with a jack and support it with jack stands placed under the frame. Locate the two oxygen sensors in the exhaust system. There is one in the front right exhaust pipe and one in the front left exhaust pipe. They are both slightly down stream from the exhaust manifolds.
Locate the wiring harness connector on the end of the sensor. Disconnect the connector and lay the harness aside.
Remove the oxygen sensor with an oxygen sensor socket and a ratchet, turning the sensor counterclockwise to loosen it. Lift it out of the threaded insert in the exhaust pipe and discard it.
Thread the new sensor into the exhaust pipe fitting and tighten it with the oxygen sensor socket and a ratchet. Plug the electrical connector into the wiring harness connector on the truck.
Move to the second sensor and repeat the process to replace it as well. Support the truck with your jack and remove the jack stands, then lower the truck to the ground.
Tips & Warnings
- Make sure to allow time for the exhaust to cool if you have driven the truck recently. The exhaust gets very hot and severe burns can occur if you try to work without allowing it to fully cool.
- Photo Credit Jupiterimages/Comstock/Getty Images
How to Read OBD2 Codes
Since 1996, every car manufactured has been required to have an Onboard Diagnostic system by law. This system monitors a car's performance...
How to Check an Oxygen Sensor for a Nissan Pathfinder
The oxygen sensor measures the amount of free oxygen in the exhaust system as an indicator of fuel mixture. The optimum fuel...
How to Replace a Nissan Xterra Knock Sensor
The knock sensor in a Nissan Xterra performs a critical job. It "listens" to your engine to make sure that the engine...
How to Replace an Oxygen Sensor in a Nissan Truck
Oxygen sensors have been installed on Nissan trucks since the early 1980s. In 1995 and 1996, an additional sensor was added to...
How to Replace a P0325 Knock Sensor on a '97 Nissan Altima
The knock sensor on your 1997 Nissan Altima mounts to the side of the engine block and uses a piezoelectric element to...
How to Replace a 2003 Nissan Xterra Knock Sensor
The 2003 Nissan Xterra uses a knock sensor mounted to the exterior of the engine block to determine if there are vibrations...
How to Replace a Knock Sensor in a Nissan Maxima
Replacing the knock sensor on the Nissan Maxima is simple, but the sensor can be expensive, so be sure to have the...
How to Replace the Knock Sensor on a 1997 Pathfinder
The knock sensor is responsible for monitoring the engine block for abnormal vibrations or internal components running out of balance. The sensor...
How to Fix a Focus O2 Sensor Problem
The oxygen (O2) sensor in a vehicle is mounted in the exhaust manifold, and it measures the oxygen content in the exhaust...