Metric taps and dies-O2 sensor fun

[james accordino]

If you ever had trouble with the O2 sensor when trying
to remove or reinstall, chasing the threads with a tap
and die will really help.  When removing the sensor
from my Dorf truck, it took a long time and took metal
off both surfaces.  The one in my 89 200q might have
been the original.  A while back I got the Craftsman
large tap and die set to augment the standard set, and
the tap and die for the O2 sensor are in there.  18mm
x 1.50, I believe.  This works very well.  Sensor can
then be screwed in by hand.  After 2+ years, it came
out very easily with no metal damage, and I didn't use
that anti-seize compound.  If you do your own work,
and have never tried doing your reassembly with nuts
and bolts that have been chased with a tap or die, you
really owe it to yourself to try it.  

Hope this helps someone avoid some pain

Jim Accordino