Hi, Don't know how well a torch would work on something like this, as
many of these Sensors-Sending Units have plastic on them.
(Although what will be going into the engine-manifold should be some
sort of metal)
A milder, less drastic method, might be the use of a soldering iron to
heat the area.
I've found that many times, using a mild-medium strength threadlocker,
like Loctite #242 on small machine screws in effect is virtually
permanent. This is where a Soldering Iron applied to the screw head can
work wonders, and it might help here?
The other thing is, is that sometimes, there are special made sockets
for removing sending units-sensors, and might be in this particular
Hope this helps, Mark