Addendum to O2 sensors

[Brendan Rudack <rudack@umcc.ais.org>]

On 11-5-98 Brendan Rudack wrote:
 
> You can do that if you wish... But for me, I don't mind having a Bosch
> O2s on my Audi even it has Ford pinstamped on the shell...if it costs
> 1/3 of the "Audi" sensor and all that is required is some soldering and
> shrink wrap. I have been told that you can even buy Audi connectors and
> assemble them yourselves... that would save the splice job. 
 
My "freshened" morning brain brought out a few more thoughts...

To add:
For standard and water resistant sensors the reference air (key to a
sensors operation) enters the sensor through the upper shield.  
Now, some sensors are labeled as water proof.  These sensors are sealed to
the atmosphere and suprisingly the reference air enters through the
stranded wires in the harness.  This air enters because of pressure
differences between the inside of the sensor and the atmosphere as the
sensor heats and cools.  The point of this is that soldering on new
connectors to standard and water resistant sensors is ok sense the sensor
can "breath" from the upper shield.  Now if you take a sealed (water
proof) sensor and solder the wires you risk killing the air
reference.  For water proof sensors (not many out there) it is best to use
butt-splice connectors and hot-melt or shrink wrap when splicing.
Personally, I would still cut off old connectors and crimp on new factory
connectors... 

A few more cents.

Brendan Rudack AKA "Bendy"
'98 A4tq 
'88 90q 2B tq pro-rally ride
Fenton, Michigan
USA