The exhaust has so many attachment points that a separate ground wire in
not necessary or even helpful. More important that you have the
deflector shield to keep airflow from cooling it off and road spray off
it. Both can cause most sensor issues. The sensor can get contaminated
from the outside. Its signal is derived from the difference on O2
content of the exhaust and outside air.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
Of Evan Mac Donald
Sent: Saturday, March 25, 2006 9:57 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Oxygen Sensor Ground

Any body got any other ideas for attaching a seperate ground to a 1-wire
O2 sensor? I don't want to trust the rusting exhaust system and its
connections. The only permanent connection I can think of is to solder a
lead to the outer housing, but I am afraid that even the upper edges get
too hot, and will remelt the solder. Can a lead be welded on? How much
heat is too much? I can braze a connection in place, if that won't
destroy my shiny new sensor.

  And that raises another question. On a newer-style, self-heated O2
sensor, is the ground only for the heating element, or does the sensor
also use that same ground?
  In other words, does the sensor ground through the housing and then
the exhaust system, or does it also use the ground for the heater?