Engine Controls - Removal of Seized Oxygen (O2) Sensors

NUMBER: JAGA309-001
*(ISSUE 2)*

*DATE: 29 APR 2008*

MODEL: ALL

THIS ISSUE REPLACES JAGA309-001, ISSUED 11 SEP 2006. CHANGES ARE SHOWN WITH ASTERISKS.

SECTION: 309 - EXHAUST SYSTEM

REMOVAL OF SEIZED OXYGEN (O2) SENSORS

AFFECTED VEHICLE RANGE:
ALL VIN: ALL
MODEL YEAR: ALL

CONDITION SUMMARY:

REMOVING O2 SENSORS WITH SEIZED THREADS

CAUTION:
This procedure applies to all O2 exhaust gas sensors. Oxygen sensor breakaway torque must not exceed 70 Nm (52 lbf-ft). A breakaway torque exceeding 70 Nm (52 lbf-ft) may indicate that the threads have become seized. Damage to the exhaust catalyst threads may occur if breakaway torque application exceeds 70 Nm (52 lbf-ft).

Situation:

This information only bulletin has been issued to inform Dealers of a procedure to remove any O2 sensor with seized threads. This method has been developed to minimize damage to the exhaust catalyst threads while attempting to remove any O2 sensor from an exhaust catalyst where the threads may have become seized.

Action:

When removing any O2 sensor, should the breakaway torque exceed 70 Nm (52 lbf-ft), refer to the Repair Procedure detailed in this bulletin to remove the O2 sensor.





PARTS

WARRANTY:

No warranty. Information purposes only.

Normal warranty policy and procedures apply.

REPAIR PROCEDURE

REMOVING AN OXYGEN (O2) SENSOR WITH SEIZED THREADS

CAUTION:
If an O2 sensor breakaway torque exceeds 70 Nm (52 lbf-ft), do NOT apply additional torque. The threads may have become seized and damage to the catalyst threads may occur with additional torque application.

*WARNING:
Use care to not cut or damage the O2 sensor electrical connector or attached wiring.*

1. Disconnect the O2 sensor electrical connector.

NOTE:
Upon removal, a 'seized' O2 sensor may turn 90 - 270° before reaching the breakaway torque threshold.

2. *Using a suitable O2 sensor socket and torque wrench, attempt to remove the O2 sensor.*

3. If the breakaway torque exceeds 70 Nm (52 lbf-ft) STOP torque application.

CAUTION:
Care should be exercised to minimize the amount of lubricant that is allowed to enter the exhaust system through the sensor hole. Lubricant can contaminate the catalyst.

4. Apply a thin coat of penetrating oil (C2A 1022 or WD40) along the exposed threaded area.





NOTE:
Turning the O2 sensor clockwise and then counter-clockwise will help loosen and distribute the lubricant throughout the threads. The back and forth rotations will aid removal of the sensor and minimize potential damage to the catalyst threads. (Figure 1)

5. Turn the O2 sensor clockwise and counter-clockwise to distribute the lubricant around the threads. (Figure 1)

6. After adequately distributing the lubricant, attempt to remove the O2 sensor.

7. If the breakaway torque exceeds 70 Nm (52 lbf-ft), STOP torque application and allow further time for the lubricant to penetrate the threads.

8. Clean the catalyst pipe threads using a 3/4 inch diameter wire brush (similar to a male battery terminal cleaning brush) to remove any debris.

9. Inspect the catalyst down-pipe threads for any damage and ensure a new sensor can be installed.

CAUTION:
A new O2 sensor must be installed as thread damage and chemical contamination to the O2 sensor may have occurred during the removal process.

*NOTE:
New O2 sensors come with an anti-seize compound already applied to the threads. If additional anti-seize compound is required, the use of Bostik 'Never Seez(R)' Pure Nickel Special is recommended. For additional information or procurement, visit: http://www.neverseezproducts.com/purenickel.htm for more information.

10. Carefully thread a new O2 sensor into the catalyst pipe threads and hand-tighten until the sensor gasket is visibly seated on the catalyst pipe flange.

11. Tighten the O2 sensor to 47.5 Nm (+/- 7.2 Nm) [35 lbf-ft +.- 5.0 lbf-ft)].





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