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Category: Buick
Satisfied Customers: 2956
Experience:  GM world class, ASE master tech w/ L1 advanced driveablity, 15yrs experance bumper to bumper
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2005 Buick Century: it to get to and replace the oxygen sensor

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How difficult is it to get to and replace the oxygen sensor for a 2005 Buick Century? where is the wire connection made? can I access it with simple tools?
The oxygen sensor is easy to replace on this engine. There are 2 sensors, the first and most common one to go out is for the engine. Its located on the back side of the engine between the firewall and the engine. Its located on the exhaust manifold, it does require a oxygen sensor socket. The socket can be bought at any auto parts store. The best thing to do is soak the sensor where it treads in with a good pentrant oil. Let it soak for a half hour. Disconnect the eletrical connector and then remove the sensor.

Removal Procedure

The heated oxygen sensor may be difficult to remove when engine temperature is below 48°C (120°F). Excessive force may damage threads in exhaust manifold or exhaust pipe.

Object Number: 73896  Size: SH
  1. Disconnect the heated oxygen sensor (HO2S) electrical connector.
  2. Use the J 39194-B to remove the heated oxygen sensor (HO2S).
To istall, just tread the new sensor in and connect the eletrical. If the check engine light was on, then you will have to have the code cleared,or the light will stay on.

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Customer: replied 8 years ago.
Thanks - before I start replacing parts, is there any simple clear way for me to know which of the 2 sensors has in fact failed? if the engine remains on, how do I know that replacing this part has solved the problem? is there anyway for me to turn the engine light off/ reset myself? are you saying that the sensor will be easier to remove with the exhaust manifold hot? should I be putting metalic anti-seize compound on the threads of the new one? are after-market replacement sensors sufficiently reliable or do I need an OEM part?..Kenneth
The only way to know what sensor is bad is to get the code from the engine. The front sensor on the exhaust manifold is the important one, this will control fuel to the engine, the rear sensor only checks the catalytic converter for proper operation and does not control any funtions, but can cause the check engine light ot come on. You might beable to disconnect the battery for a few hours, sometimes this will clear any stored codes, or you can take the car to a auto parts store, they will clear it for you if you buy the part from them. I would recommend using the GM part, It will work the best, XXXXX XXXXX are muti-fit parts and are not designed for your car but designed to fit most cars.
I would start the engine and let it run for 1 min to get the manifold warm, not hot. Most sensors will have anti-seize already on the treads, but if they do not, I would apply some on to the treads. The only way to know for sure if the new part has fixed the problem would be to read the egine data from a scan tool, or clear the code and drive the car. If the light does not come back on after a few trips, then the problem is gone.
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