[Fwd: Re: '86 CGT oxy sensor]

[Gary Erickson]

I had originally sent this directly to Craig, but it looks like I should
have replied to "all."  ;-)

-Gary

-------- Original Message --------
Subject: Re: '86 CGT oxy sensor
Date: Tue, 03 Oct 2000 08:56:37 -0700
From: Gary Erickson <erickson at teleport.com>
To: "Craig D. Niederst" <niederst at telerama.com>

"Craig D. Niederst" wrote:
 
> With all this oxy sensor talk, I know my '86 CGT is in need of a new one. It
> currently has a one wire sensor in it now. I noticed that while this 1 wire
> sensor plugs directly into a single socket plug on the factory harness,
> there is a 2 wire socket on the same harness that is unused. Does the '86
> CGT take a 3 wire heated sensor, or is the 1 wire one correct? I've looked
> in the family album, and its inconclusive. I am hoping replacing this sensor
> will correct the horrible idle problems and the poor gas mileage (~12 mpg
> according to the trip computer). TIA.

Craig,

The Coupe GT's still had the oxygen sensor mounted in the downpipe from
the manifold (rather than in the neck of the catalytic converter like
the 4kq's).

That location is warm enough that Audi continued to use the single-wire
sensor in the GT's through the end of their life.  (The mythical
high-compression 2.3l special edition GT's sold as '87.5 models may be a
different story)

The 2-wire socket that you are referring to is a test point for the CIS
system to plug in one of the diagnostic tools.  Even if you do find 12V
there, I wouldn't recommend trying to use it as a power source!  ;-)

The single wire OXS is the correct replacement, if you were willing to
wire up a power source that was switched with the ignition, you could
easily install a three wire OXS, but I'm betting any gains would be
minimal.

HTH!

-Gary

'85 turbo GT coupe
'89 80q
'89 200q