On 24 Jul 96, David E Most wrote:

> Ok, here's the story.  I've taken out the muffler and cat. converter.  
> The O2 sensor is really stuck in the converter. so,
> 
> 1)If I use heat to get it out, will it damage the sensor?

likely.  they are meant to stand gobs of heat from the underside, not 
much on top.  use penetrating oil for several days before trying 
heat.
> 
> 2)Should I replace the sensor anyway since it's probably original?

simply, yes.
> 
> 3)Is it nec. to have a working sensor for the engine to run well?
mostly.  you will get better mileage, fewer emissions, and a reduced 
likelihood of engine damage due to the mixture being out of whack if 
a working sensor is connected.

> 4)Is it nec. to have a working sensor to pass emissions tests?
>
yes. and no.  the sensor 'fine tunes' the mixture greatly increasing 
the chance you will meet emission standards.

> 5)Finally, since I've had my '87 (few weeks), I've noticed that only the 
> large plug coming out of the O2 sensor is connected....the little plug 
> was just hanging loose.  Someone told me that this means that the O2 
> sensor wasn't really hooked up anyway.

the large plug is for the heating element of the sensor.  the single 
wire is the actual output of the sensor.  yes, it is currently not 
hooked up.

let me spend your money for you... buy a new one  :)

you can test your sensor once it is installed in the exhaust system.  
check the archive files for my article on that.  if the sensor tests 
okay, save your money.

-dan