This is fairly easy to check.  Disconnect the large connector at the ECU,
and disconnect the O2 sensor.  Open the ECU connector shell on the harness,
and you will see the cable (sorry, but I don't have a manual with me to give
you the pin numbers).  Using your multimeter on a Rx10K or so scale, measure
betwen the shield and center conductor of the cable.  While checking it,
wiggle the cable for it's entire length.  If you see any resistance other
than infinite, there is a problem.  I have replaced several of them, and
used shielded microphone cable successfully.  At the end where you strip the
shield away, be sure to use some heat shrink on it to prevent moisture from
entering the cable.  This is an easy repair.  Good luck.
Steve Sandlin
http://www.steveslockshop.com
'84 Wolfsburg Westy
'79 Transporter
'00 New Beetle
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