Above the edge of each joist, drill (4) 1/2" holes centered over
the joist and approximately 4" OC parallel to the joist and 2" OC
across (spanning) it. Insert a saber saw with 1-3/4"
long blade through the hole and cut across the joist and alongside
it, connecting the holes. Pry the 1-1/2" plywood out of the hole
and set aside. This will expose approximately 4" of the joist.
Using a longer blade in the saber saw, cut a 1-1/2" to 1-3/4" wide
slot in the joist, breaking the piece out. This will leave you
with a rectangular cut in the joist adequate for your 1-1/2" pipe
or conduit.

Glue and screw the removed plywood flooring back over the joist
after you've run the pipe, leveling it with floor patching
compound.

--
Nonny
When we talk to God, we're praying,
but when God talks to us,
we're schizophrenic.
What's the deal?