Contour Enthusiasts Group Archives Forums General Troubleshooting O2 Sensor fix

My check engine light came on about a day ago, so I took my car to Auto Zone and they said that the O2 sensor needed to be replaced. They asked me if the sensor was before or after the cat and I said before, I think. So today when I was looking in the Haynes Manual it looks like it is before the cat. Is this correct? Also how hard is it to replace the O2 sensor. Anybody have a how-to on how to do such a thing, I looked in the Haynes Manual and there wasn't anyting. If there is something in Haynes what page would it be on? Thanks in advance.

Hey!! I just replaced mine - My car is a 4cyl - not sure how much difference - but there are 2 sensors. The pre-cat is right in the front of the engine on the manifold - I needed a slotted socket to fit in there because of the surrounding heat sheild and the wiring gets in the way. You can borrow from AutoZone. The other is on the rear of the manifold near the oil filter. The page in the Haynes manual is 6-15. Good Luck!

Originally posted by COntour:

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So today when I was looking in the Haynes Manual it looks like it is before the cat. Is this correct? Also how hard is it to replace the O2 sensor.

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Your car has four O2 sensors. Two on each bank. On each bank, there is one before the cat and one after.

If you do a search, you will find plenty of threads on O2 replacement.

How many o2's does a 95 SE have? I heard 2 but I'm not sure!

'95 v6 has 2 O2 sensors.
'96+ have 4.