where is the o2 sensor located on my 1997 f 150

The O2 Sensor is mounted to the side of the exhaust system. There are two
sensors. One is located as near as practical to the engine, physically on
the exhaust manifold -- the manifold is the piping that carries the exhaust
from the cylinders to the muffler and out the tail pipe. You will find the
first O2 Sensor where all of the individual manifold pipes blend into one
pipe that then carries the exhaust toward the back of the car or truck. The
other sensor is located immediately after the Catalytic Converter (CAT). The
sensors are easily identified because they have wires connected to them. The
only reason to have wires connected to the exhaust system is to support the
O2 Sensors.

Why are you asking?




"lynn" <dalscwb1 (AT) yahoo (DOT) com> wrote

On Feb 25, 3:34 pm, "Jeff Strickland" <c... (AT) verizon (DOT) net> wrote:
I have a check engin light on and had it checked and was told the 02
sensor needs replaced.

"lynn" <dalscwb1 (AT) yahoo (DOT) com> wrote

Well Lynn,

You have 2 O2 sensors on your truck. Both are located in the Y-pipe just
after the exhuast manifolds.

First locate both sensors, then figure out where they plug into the harness
at. It shouldnt be more than 30" away from the sensor, just follow the
wires. They are usually connected at the back of the engine..

Next take the truck out for a nice drive (about 10-20min), to get the truck
up to operating temp, and get the O2 sensors working. They have to reach
600*F before they start signalling the computer, and your truck has to run a
certain amount of time before they start working...

Then take the truck home and leave it running. Pull each sensor loose (one
at a time), and check for a varying voltage signal on the grey/light blue
striped wire for the right sensor, and red/black striped wire for the left
sensor. If that checks out then do this..

On those same two connectors, switch your voltmeter over to OHMS. Then put
your positive and negative lead between the red wire and yellow/light blue
striped wire on the left sensor, and between the red and the red/white
striped wire on the right sensor. You should have between 3 and 30ohms
resistance in both heaters. If not replace the sensor (s) with the high or
low resistance..

Basically if one isnt signalling, or the heater is shorted in one of them,
then that is the one that needs replaced.. Which bank is it saying has the
problem? Bank 1 or 2?

After you identify which sensor is giving you problems, then you need to
figure out why.. Have you used any octane boosters lately? Had any engine
work done lately in which silicone gasket maker was used? Burning any oil?
The list goes on for this part, but that gives you an idea of what can make
these fail prematurely..

Ford Tech

"lynn" <dalscwb1 (AT) yahoo (DOT) com> wrote

You have to find out WHICH sensor needs to be replaced. Ford Tech says you
have two, one on each manifold. I suggest you have at least two, one on each
manifold, and one after the CAT. In any case, you can troubleshoot the
sensors as Ford Tech describes, or you can pull codes and let the computer
tell you which sensor seeks your attention. I would pull codes ...

(At this point, we really don't need to discuss the total number of sensors
and I may regret bringing that topic into the discussion. What we need to
know in order to provide the best information on where to look next is the
code(s).) Once the code(s) is(are) known, then we will be able to say
precisely where the sensor is that is asking for your time and money.

"David M" <NOSPAM (AT) nospam (DOT) com> wrote

EVTM only showed 2 sensors. I dont think ford used an after cat sensor on
the prior 2000 MY trucks..

Ford Tech