O2 sensor's

[Mike Fahrion]

New (OBDII) cars have a 2nd O2 sensor downstream of the cat.   The resulting
signal is analyzed in comparison of the upstream (normal location) O2 sensor
to determine if the cat is good.  Monitoring all emissions critical
components is an EPA requirement.  I don't think this second sensor is any
part of the closed loop fuel system.

-mike


>I've heard it should ALWAYS be put before the converter, as the
>converter's action will give false readings to the sensor, if the sensor
>was mounted paste the converter, esp if the converter is air injected,
>(either by stock design, or by holes..)
>
>Dave
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