<<<Would any one knw what the thread/pitch/tap size is for the oxygen
sensor?  I
am not having any luck with the archive. I want to chase the threads in the
cat befor i put a new one in They are kinda crusty.>>>

It is 18 x 1.5mm.  I went through this a few months ago when trying to
find something to fill the O2 sensor hole in my new catalytic converter. I
ended up using a 18 x 1.5 oil drain plug. It would have been much cheaper
put a spark plug in there, but it looked too funny for my taste.

Brian
84 Westy 'The Ark'