Where is the O2 sensor on a Ford Taurus and can a backyard mechanic replace it?

Answer 1

You can probably change the sensor yourself. But you have to know which one is bad. You will also need to buy an O2 sensor wrench. It's very difficult to get out without the proper wrench. It actually looks more like a socket to fit around the sensor, but it has a slot cut in it to allow for the wire.

There are 4 o2 sensors on a Taurus. 1 on each exhaust manifold, and 1 after each catalytic converter.

And before spending any money on replacing a sensor, I would test it to ensure it really really has failed! It's very likely someone read the DTC (diagnostic trouble codes) that cited an oxygen sensor reading - but then said something that leads you to believe it's a failed/bad sensor and needs replacing. The vast majority of times that is NOT the problem.

Take those codes and research them on the internet! (see "Related Links")

A perfect example are P0171 and P0174 codes - indicate a lean mixture was read in bank 1 & 2 (respectively). On the Windstar, that's a prime symptom covered in Technical Service Bulletin TSB# 03-16-1. The auto parts store guy had me ready to spend $80 on 2 sensors. - CCoach

I've added a link that will show you approximate prices for a 3.0L V6 OHV Vulcan's O2 Sensors along with a link to the locations for the O2 Sensors locations for said engine.

3.0L V6 OHV "Vulcan"

3.0L V6 DOHC "Duratec" with 24 valves

The oxygen sensor is located below the engine in the exhaust pipe before the catalytic converter and muffler. It is mounted in the pipe with wires going to it. You need a special socket to remove it in most cases but sometimes you can do it with a wrench. When replacing it be sure to put anti seize lubricant on the threads so it can be serviced again in the future.

DIY Procedure:

I've replaced the upstream O2 sensors on a 2005 Duratec without removing the upper air intake manifold. Critical procedure is to disconnect the plug with only the left hand on the rear sensor. By touch as it can't be seen for disconnect. Practice on the front sensor so you understand how the release works. Takes some patience. I used a standard O2 socket and 1/2 inch drive to remove the sensor. It came easily but if a sensor has been installed for 100k miles or more may need to warm by running the engine for 5 - 10 seconds and penetrating fluid to help. I change at 100k, when smog tests indicate a rise in HC or NO, or Car Chip shows the LTFT not to be where I want it. Upstream O2 sensors are critical to performance and mpg. Cost was $42 per Bosch sensor online. Add a little antiseize to the upper threads/shoulder. Not on the tip.

Answer 2