I just remembered an amazingly good heat-to-loose trick.
After the thread area is good and not..
stick a candle there..
the wax gets sucked right in, and often will make your fastener very
unscrewable.

i keep a candle or two right by my heating/welding workbench to help
remember this trick.
Scott

On 10/2/2015 3:55 AM, Larry Alofs wrote:
> When fighting a tough O2 sensor, I have found that special O2 sockets are
> too weak because of the slot for the wire.  A stout box wrench is best if
> the connector is small enough to fit thru it.  Of course if you are cutting
> the cable off anyway, that doesn't matter.
>    Recently I had one where I had to put the cat in a big vise, heat the
> bung red hot, and use a box wrench with a pipe extension.  Probably would
> have damaged the element inside the cat, except that it had already
> disintegrated and been disposed of.  I just wanted to prove to my self that
> I could get the remains of the sensor out.
>    What fun,
> Larry A.
>
>
> On Fri, Oct 2, 2015 at 9:43 AM, Richard Koller <brvkoller@gmail.com> wrote:
>
>> Dennis,
>> I had this same problem and I heated the cat at the junction where the O2
>> sensor screws in with MAPP gas. Then quickly slipped my 22mm box end over
>> the disconnected sensor wires and was able to break it free. It would be
>> better as others have said to use the dedicated O2 sensor socket. Heat was
>> essential however in my case.
>> Good luck.
>> Rick Koller
>>
>> On Thu, Oct 1, 2015 at 12:37 PM, Dennis Jowell <dennisjowell@gmail.com>
>> wrote:
>>
>>> I just started to replace my O2 sensor on my 2.2 wbx. No,luck using my
>>> wrenches . Everything is rusted together. The catalytic converter is only
>>> about a year old. Is there a better way to remove the sensor? Should I
>> use
>>> my touch to heat the sensor ? Any ideas would be great. I might get to
>>> Quebec yet just have to get this done.
>>>
>>> Regards,
>>> Dennis
>>>
>>> Dennis Jowell
>>> Scotch Hollow Farm
>>> Newbury, Vermont
>>>