Re: O2 Sensor

[Bill Draeger <triliad@earthlink.net>]

Mark Eissler wrote:
> 
> gregsj@mail.imm.com wrote:
> 
> >A few weeks ago, with regard to my '91 200 TQW, I asked for more
> >information as
> >to exactly what the O2 sensor does, what it should cost to replace it, and
> >whether a "shade-tree" mechanic could to it or if it requires a "real" Audi
> >mechanic. No answers as yet -- I sure could use some help. TIA. Greg
> >
> 
> The 02 sensor works in conjunction with the fuel control computer. It
> measures the exhaust gases and sends the info back to the computer which
> determines whether or not your engine is running too rich or too lean and
> makes the appropriate adjustments.
> 
> If the sensor is bad, you will likely notice some power loss and along
> with hesitation.
> 
> You can replace the sensor yourself. You will likely want to purchase an
> 02 socket that has a groove in it for the wire that's permanently
> attached to the top of the sensor. The sensor is located in the exhaust
> pipe near the engine.
> 
> One more thing to note: gasket sealer and any other compound that may be
> used in conjunction with the crankcase, valve cover, etc. (generally any
> part of the engine that may come into contact with the oil in the engine)
> MUST indicate that it is "oxygen sensor safe." These compound can wreck
> an 02 sensor.
> 
> Hope this helps.
> 
> Mark Eissler          | UNIX, DOS, oh and MacOS too.
> tequila@interlog.com  | Why wouldn't a developer use
>                       | a Macintosh?
> http://www.interlog.com/~tequila/  My new hURL!!!!!!

Thanks for the input, Mark, about the O2 wrench. I also agree with your
input for when to replace. I have a '90 V8Q which exhibited these 
symptoms at about 60K miles (when Audi suggests replacement anyway).
Fortunately, the dealer was able to get it covered under extended 
warranty. I also have an '88 5K with 135K miles and never replaced
the O2 sensor but when it fails have also been tempted to do it 
myself because "it's right there".

Bill Draeger