John-
You
probably already have this covered...but just in case...make sure
you
don't have any Teflon tape or pipe thread sealant on you single
wire
sensors. They are grounded through the housing and Teflon tape
and
thread sealant insulate them from the engine ground.
------------
Well, I don’t know - I used thread
compound on the sensors, then measured resistance from sensor case to ground. Zero
(below 1 miliohm) in every case. I think a light coat of thread compound
is important to lube and seal, and a well tightened tapered thread is going to
give good contact.
FWIW,
Al