"'Curly Q. Links'" <motsco__@interbaun.com> wrote in message
news:44199C0A.56B0B96D@interbaun.com...
>I once saw a web page where a guy claimed you could make an O2 sensor
> work like new by boiling it in bleach, (or something like that). I've
> got three Hondas (six O2 sensors) that might benefit from such a
> 'trick'. :-)
>
> I tried Google but didn't find it.
>
> Anybody got some GOOD links to Oxygen Sensor diagnosis / helps?
>
> I have access to a basic oscilloscope and other tools. I know Bosch is a
> dead end, but they are as reliable as volkswagen :-(
>
>
> Thanks, 'Curly'

The best explanation I've seen, complete with test info, is from Rick
Kirchoff http://www.mr2.com/TEXT/O2_Sensor.html

I've used a scope with some success before. Set the vertical up DC coupled,
to read a 0 volt to 1 volt range, and about 100 ms per division sweep. You
will see the .45 volt bias Rick describes until the sensor warms up, then it
quickly moves into the 0 volt to .9 volt transitions. The waveform is very
incoherent, of course, but you will see very rapid transitions... IIRC, on
the order of 10 ms for a good sensor. At idle the transitions should be
continuous; if you see periods when the transitions pause even though the
engine operation is steady there may very well be vacuum or fuel leaks. The
one I was looking at had a dripping throttle body injector. The ECU would
acquire an idle mixture for a second or two, then the voltage went high
(rich) and the ECU chased it until the mixture was lean and it had to find
the correct setting again. Stupid Taurus!

Mike