The O2 Sensor Is Stuck in the Manifold

The oxygen sensor in your vehicle monitor the amount of oxygen that is left over after the combustion process, and are used to help the computer adjust the air-to-fuel ratio accordingly. Since oxygen sensors only can be mounted in the exhaust system, they are subject to expansion and soot buildup over time.

Instructions

Removal

1

Park the vehicle on a level surface and set the parking brake. Lift the vehicle hood and support it with the hood prop rod. Allow the engine to cool completely before continuing.

2

Lift the vehicle into the air with a floor jack and place jack stands under the front subframe. If the oxygen sensor is on the lower end of the exhaust manifold, lower the vehicle until it securely rests on the jack stands.

3

Spray penetrating oil around the base of the oxygen sensor and allow it to sit for a minimum of five minutes. Follow the oxygen sensor pigtail to its connection at the vehicle wiring harness and disconnect the pigtail from the harness.

4

Install the oxygen sensor socket over the oxygen sensor so the pigtail extends through the slot in the socket. Attempt to rotate the oxygen sensor counterclockwise with a ratchet and oxygen sensor socket. Tapping on the end of the ratchet handle in a counterclockwise direction can help break the sensor loose. Rotate the sensor back and forth from tight to loose, if free. Remove the socket and apply more penetrating oil; allow it to sit for five minutes.

5

Install the oxygen sensor socket, then remove the oxygen sensor with a ratchet, if possible; do not use excessive force.

6

Remove the socket from the oxygen sensor if it does not break loose. Put on heat-resistant gloves. Ignite the propane torch and apply heat to the base area of the manifold around the oxygen sensor. Continue to apply heat until the area is very hot and begins to change color.

7

Install the oxygen sensor socket onto the sensor and rotate the sensor counterclockwise with a ratchet. Remove the sensor by hand once the sensor is loose enough to do so. Inspect the manifold for any damage to the oxygen sensor mounting threads; repair as necessary.

Installation

8

Compare the original oxygen sensor to the new sensor if the sensor is being replaced. If the sensor is not being replaced, clean the original sensor threads with a wire brush until clean. Apply a coat of copper anti-seize to the threads of the oxygen sensor; this may be pre-applied on new sensors.

9

Thread the oxygen sensor into the exhaust manifold by hand. Install the sensor socket over the sensor so the pigtail extends through the opening. Rotate the sensor clockwise with a ratchet until it is tight. Remove the ratchet and sensor socket. Connect the sensor pigtail to the vehicle wiring harness.

10

Lift the front of the vehicle off the jack stands with the floor jack and remove the jack stands. Lower the vehicle to the ground. Start the engine and check for any leaks around the sensor.