Well, if the O2 sensor isn't working, that is, not generating voltage in
response to chenges in air/fuel mixture, then disconnecting it would
produce no change in the measurements because the sensor "wasn't there"
in the first place.

When the O2 sensor isn't sending a signal to the ECU then the ECU is
supposed to default to a somewhat rich mixture (hence your high CO) which
will typically be pleasing to the driver, even if the environment doesn't
like it.

On Mon, 25 Oct 1999, Jose R. Moscoso wrote:

> Today I took my '84 Westfalia for state-required inspection after installing
> the muffler and catalytic converter bought from BD.  Surprisingly, the
> W***F***** didn't pass the test because of high CO measurements in high RPM.
> The guy doing the inspections argued that my problem is a bad Ox sensor
> which he disconnected to prove his point without no change in measurements.
>
> I find my van to run quiet acceptable and I am worried about contamination,
> what is the verdict from the gurus.  What is the use of this sensor if it
> doesn't seem to produces any change in the running of the van.

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Tom Young               young@sherlock.SIMS.Berkeley.EDU
Lafayette, CA  94549    '81 Vanagon
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