Where are oxygen sensors located and what are the names - designations - Taurus?

Here is the low-down on oxygen sensors, and their location designations explained:

Oxygen sensors are screwed into the exhaust system at various points. Some people say that there are 4 oxygen sensors, but technically, that is not correct. Only the front 2 are considered oxygen sensors.

These oxygen sensors are screwed into the exhaust pipe or directly into the exhaust manifold, one on each bank. Because they are in front of the catalytic converter, this is often referred to as 'upstream'.

The other 2 are actually called catalyst monitors. They are oxygen sensors, but they serve a different purpose. They monitor the activities of the catalytic converters, thus the name, catalyst monitors. They are screwed into the exhaust one on each bank, after, or downstream, of the catalytic converters.

On a 4 cyl engine, there are only a total of two such sensors, the one in front of the catalytic converter is the O2 sensor, the one behind the cat is the catalyst monitor.

The location names for them are as follows:

• On a 4 cyl, the front / upstream is called "bank 1 sensor 1" and the rear / downstream sensor is called "bank 1, sensor 2."
• On a V6 or V8 engine:
  • the passenger side bank on a forward facing engine, or the bank closest to the firewall on a transverse mounted engine, is bank number 1, so the forward / upstream sensor on that bank would be "bank 1, sensor 1."
  • The driver's side bank (forward facing mount engine), or front bank (transverse engine) would be bank number 2, thus the forward / upstream sensor on that bank would be "bank 2, sensor 1," and the rearmost / downstream sensor on that bank would be "bank 2, sensor 2."

NOTES:

• Use lots of penetrating oil - allow to soak - to make removal easier and avoid damaging the exhaust pipe
• the sensors are screwed directly into the pipe at a 90 degree angle and look like spark plugs with either 8", 12", or 14" wires attached to them
• Tools:
• it is usually a 7/8ths size wrench
  • special-purpose oxygen sensor socket - not expensive, and commonly offered for free use by the auto parts store
• Inspect the condition of wires and that they are not touching any parts of the exhaust system
• No special tool is required if you are not reusing the old sensor. Simply unplug sensor harness from vehicle harness then snip off the wires at the sensor. This will allow you to slip a 7/8" box wrench over the sensor for a tight, no slip grip for removal. Use the 7/8" open end wrench for installation of the new one.

NOTES:

Rule of thumb: Bank 1 is on the side of the engine with cylinder #1

6 Cylinder numbering:

-----

1 2 3

4 5 6

----

Front of vehicle

Answer - EditorialAnd before spending any $$ 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 (see "Related Questions")

The auto parts store guy had me ready to spend $80 on 2 sensors. - CCoach

There are 4 O2 sensors on your Taurus. 1 is under each exhaust manifold and there are 2 just before the Y pipe. If it shows no. 2 on the scanner it is on the front side near the radiator. If it shows no. 1 it is near the fire wall - the side of the engine with cylinder #1. 3 and 4 are located just before Y pipe but I don't know which one is which. its located on the right hand side of the engine when you are facing forward with the hood up its located in the lower right hand corner Under hood, center, lower engine area, front side of engine, mounted in exhaust pipe .

Oxygen sensors are always screwed into the exhaust manifold as they sense the amount of oxygen in the exhaust and tell the computer how to mix the air fuel ratio. More or less.

just in front of the cat converter.. on each pipe... There are four (4)oxygen sensors on the 96 Taurus the two in the back are screwed into the tailpipe on both sides of the Catalytic converter. They are on the top of the pipe so hard to see, but you'll see the wires coming off them. The other two are at the front of the engine. the sensors are located on the upstream and down stream of the exhaust system..one under the car behind the catalytic converter and one just in front at the top of the exhaust system comming out of the engine block.where is #1 sensor located ?