Diagnosed at Auto Zone as needing a front O2 sensor?

DON ERWIN

MEMBER
1999 FORD CONTOUR
4 CYL
FWD
AUTOMATIC
160,000 MILES

My car was diagnosed at Auto Zone as needing a front o2 sensor. First, is this somthing that can be done without having to remove other car/engine parts etc and are there any special tools required to perform this. The check engine light is on and I am due for a GA emissions check to register the vehicle

1 Reply

SQM

MECHANIC
6,383 POSTS

Hello,

Replacing the front oxygen sensor can be done relatively easily. You just have to move the exhaust manifold heatshield out of the way before you can access the Oxygen sensor.
You can take off the Oxygen sensor with the correct size wrench. However there are special sockets made specifically for O2 sensor removal and installation, can make it easier for you.
Those sockets are readily available at your local auto parts store.
It is always a good idea to spray penetrating lubricant on the oxygen sensor before removing it as the sensor typically gets seized due to heat form the manifold.

You might find these articles helpful:

https://www.2carpros.com/articles/how-an-oxygen-sensor-works
https://www.2carpros.com/articles/how-to-test-an-oxygen-sensor-02-sensor
https://www.2carpros.com/articles/how-to-replace-an-oxygen-sensor

I have attached the diagrams for your reference.

Please let me know of any questions.

Thank you.

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