Arlene,

Get another mechanic if he or she said that you need to replace the O2
sensor just because that light came on.

That light comes on every 50k miles (maybe some other distance in metric
odometer van) and is turned off by pushing a button underneath the front
driver's side of the van.  You have to remove the spare and leave the
clamshell dropped to get at it IIRC.

How to reset it by list member Bob Stevens from search of email on my
computer.

"Small black plastic "box" about 1 1/2"X2 1/2"X2 1/2" square, located just
inside left (driver side) main frame tube, and just outside the steering
knuckle. Has 3 wires (blue, green, brown) coming out of its forward side.
The plastic "hole" that sticks out of this front side near the wire
harness/plug, is the place you stick something fairly pointy (thin, small
screwdriver) to reset. I can't see inside this hole due to the location of
the unit but it worked for me when I did this."

bob

The light doesn't mean you need a new O2 sensor.  If the mechanic says
it does, he is at best wrong, and uninformed, and at worst trying to
steal your money.

Your O2 sensor isn't bad unless the van has operational symptoms related
to a bad O2 sensor, or if the mechanic did the tests found in the
Bentley manual to check its operation.  A set of files related to
general FI system diagnostics is attached as well as a set of files
specifically related to the O2 sensor.

Removal and replacement of the sensor  is simple in one sense.  You
unplug it and unscrew it from the threaded hole in the exhaust.  Put the
new one in and plug it back in.  There should  be, but rarely is, a heat
shield there.  Sometimes the removal of the sensor is very difficult
because it is in so tight.  It might take spraying it with something
line PB Blaster several times to get it out.

It is very much a do it yourself project.

Sam

--
Sam Walters
Baltimore, MD

89 Syncro GL, Zetec Inside
85 Westy Weekender
85 Mercedes Benz 300D Turbodiesel - to become veggie oil powered

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