If you know what the plugs looked like before when the original O2 was
failing, this would help, but cleaning the plugs, running engine, then
checking plug colour, might suffice. You could also check the O2
output with a voltmeter then check continuity and quality of
continuity (move wires around to look for intermittent breaks) in the
O2 wire(s) to/from the ECU connector. There is likely also a
"reference" ground wire between the block and ECU.

Neil.

On 7/29/14, Don Hanson <dhanson928@gmail.com> wrote:

>    .... and I have driven the van about without the O2
> sensor...it runs just fine, but I think I am getting poor fuel economy and
> there is a sooty deposit on the bumper by the exhaust tip...Anyhow, my new
> Bosch single wire sensor came from Van Cafe and I just installed that,
> started the van and ran it till it was fully warm....without any stumbling
> or missing...There is no cat in this van, by the way...But here is the odd
> thing...I can't really tell any difference in the way it runs....It ran
> 'perfect' without the sensor hooked up and it now runs perfect again with
> the new one installed...But I would like to know if I now have fixed the
> whole problem or if I actually still have a problem between the O2 sensor
> and the ECU......and now maybe the wires aren't really connected and the
> sensor is still in op...
>
>  so my new question is:  Is there a Backyard Mechanic way to tell if the O2
> sensor is now functioning as it should be?

--
Neil n

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