Engine Controls - Seized O2 Sensor Removal Procedure
Classification:
Page 217
EM09-016
Reference:
ITB10-008
Date:
January 19, 2010
REMOVAL PROCEDURE FOR SEIZED EXHAUST SENSOR
APPLIED VEHICLES:
All Infiniti vehicles
SERVICE INFORMATION
If an exhaust sensor is seized in the exhaust manifold/catalyst/front tube perform the procedure described in this bulletin to remove the sensor and
prevent unnecessary replacement of the exhaust manifold/catalyst/front tube.
In most cases this procedure is successful. This is because the threads of the exhaust sensors are made of a softer material than the part they thread
into on the exhaust manifold/catalyst/front tube.
NOTE:
The replacement of exhaust manifolds/catalysts/front tubes for stripped exhaust sensor threads may not be considered a warrantable expense.
This procedure can be performed by two methods:
Method # 1. If the Sensor Can Be Easily Accessed
^ The procedure can be performed on the vehicle.
^ The exhaust manifold/catalyst/front tube will not have to be removed.
Method # 2. If the Sensor Cannot Be Easily Accessed
^ The exhaust manifold/catalyst/front tube must be removed from the vehicle.
^ The procedure will be performed with the part clamped in a vice.
Method # 2 is described in this bulletin. Method # 1 is the same as Method # 2 except that it is performed on the vehicle.
SERVICE PROCEDURE
Rust Penetrant
Recommended rust penetrants to be used in this procedure:
NOTES:
^ Rust penetrant is considered a shop supply.
^ Nissan Rust Penetrant can be ordered through the Nissan Direct Ship Chemical Care Product Program: Website order via link on dealer
portal.
^ WD-40 is available from various local sources.
Removal Tool
^ When removing a seized exhaust sensor with a specialty socket (which contains a slit to accommodate the wiring harness) it may spread open
and strip the sensor.
^ Before this occurs it is recommended to cut the wiring harness from the sensor and use a box end wrench or 6-point deep well socket.
1. Clamp the exhaust manifold/catalyst/front tube in a vice.
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2. Spray the sensor with the rust penetrant for 2 to 3 seconds.
^ It is important that the spray is directed at the base of the sensor to ensure it penetrates into the threads.
- Loosen the sensor approximately 10 degrees.
- Spray with rust penetrant again for 2 to 3 seconds.
- Tighten the sensor 10 degrees then loosen the sensor 10 degrees.
^ Repeat this motion several times until the sensor begins to turn more easily.
- Continue the tightening/loosening motion while gradually unscrewing the sensor. Stop when the sensor will not unscrew any further.
- Spray with rust penetrant again for 2 to 3 seconds.
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- Repeat steps 6 and 7 until the sensor is removed.
- Use compressed air to remove any metal debris from inside the boss threads.
CAUTION:
DO NOT perform this step if the procedure is being done on the vehicle (Method # 1). Doing so may cause metal debris to enter the engine
cylinders.
10. If metal debris remains trapped in the boss threads use a spiral nylon brush to remove it.
- Spray the boss threads with rust penetrant for 2 to 3 seconds.
- . Run a thread chaser through the boss to clean the threads.
^Use Kent Moore part number J-43897-18 or J43897-12.
13. Use compressed air to remove any remaining debris.
CAUTION:
DO NOT perform this step if the procedure is being done on the vehicle (Method # 1). Doing so may cause metal debris to enter the engine
cylinders.
- If metal debris remains trapped in the boss threads use a spiral nylon brush to remove it.
- . Tilt the manifold/catalyst/front tube so that the metal debris falls out of the part.
- . Apply compressed air through the boss to blow out any remaining debris.
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CAUTION:
DO NOT perform this step if the procedure is being done on the vehicle (Method # 1 ). Doing so may cause metal debris to enter the
engine cylinders.
17. Install the new sensor as described in the applicable Electronic Service Manual (ESM).
