Date:         Fri, 26 Jul 1996 15:40:35 -0400
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         DHaynes57@aol.com
Subject:      Re: O2 sensors: 1-wire to replace 3-wire?

In a message dated 96-07-26 01:37:39 EDT, farchmir@milwaukee.tec.wi.us (Randy
Farchmin) writes:

<< With that in mind, here are a few questions for those in the know:
 (I checked the archives, but didn't find definitive answers to these)
 
 1. Is it possible/practicable to use a 1-wire to replace the 3-wire?
 
 2. Will the slower warm up time of the sensor w/out the heater be a problem?
     (i.e., do I *really* need the heated sensor for good functionality?)
 
 3. Do both types have the same output voltage?
 
 If I must use a 3-wire on the 86, does anyone know of a source for an
 equivalent but, less expensive sensor?  [ the # on the part appears to be 0
 258 001 051. ] 
  >>
To answer the above questions, I offer the following:
1)  Do not replace the sensor with the wrong type.  The heater is needed both
for quick warm up, and during extended idling.  Not having the heated sesor
can cause all sorts of wierdness during engine warm up.

2)  See above.  in fact I have converted many earlier vanagons to the 3 wire
to solve that quirky idle hunt during winter.  It seems the placement in the
exhaust does not always get the sensor hot enough.  Most cars have the sensor
mounted in the cast iron manifold.  Maybe that is why VW moved it too the
Cat.

3) Both sensors do have the same output voltage.  A Standard SG-24 will worl
fine excet the little shield will not fit.  Cost about $50.00 at FLAPS.  You
will have to splice into harness.

Hope this helps,
Dennis H.