OK Gang,    Some more ....When I did, at first, connect up a Bosch single
wire O2 sensor I was not 100% certain of it, having had it in a baggie
under my bench now for a year or two.   Everything ran great for a few
hundred miles then the O2 sensor symptoms came back...intermittent rich and
over rich...
  So I got another brand new one.  I found the first one was very very
loose...finger tight at best.  It was not finding a good ground in the
exhaust bung...

I then tested the two side by side (I think I found that link on my own
also) and both worked, so now I have a tested almost new one back in my
spare parts bin...

On Fri, Oct 31, 2014 at 3:50 PM, Dennis Haynes <d23haynes57@hotmail.com>
wrote:

> I use a flashlight type "C" or "D" cell.
>
> Dennis
>
> -----Original Message-----
> From: Craig C Forney [mailto:craig@opus.com]
> Sent: Friday, October 31, 2014 6:49 PM
> To: 'Dennis Haynes'; vanagon@GERRY.VANAGON.COM
> Subject: RE: Single wire Oxygen sensor: Substitution report..
>
> I am not sure if it would cause any damage to the ECU, but I would be wary
> of putting 12V on the oxygen sensor input to the ECU, as it is only
> expecting a low amperage signal between 0 and 1V.
>
> If 12V indeed has no bad effect on the ECU, and convinces the ECU that it
> is
> a fully rich condition, then I would agree that this would certainly would
> cause the engine to go lean.
>
> However, if you are just checking to make sure that there is continuity on
> the wires, grounding the input, causing the engine to run rich, would
> probably be sufficient.
>
> Craig in Cupertino
>
>
> > -----Original Message-----
> > From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On
> > Behalf Of Dennis Haynes
> > Sent: Friday, October 31, 2014 2:03 PM
> > To: vanagon@GERRY.VANAGON.COM
> > Subject: Re: Single wire Oxygen sensor: Substitution report..
> >
> > The sensor does need a return path and it is done through the exhaust
> > and engine. There has to be a complete circuit. The ECU sensor input
> > can also be tested with a battery. Ground the input and the engine
> > should go rich, connect the battery positive terminal to the lead and
> > ground the negative and the engine should go lean.
> >
> > Dennis
> >
>