*********************
Do not drive this vehicle until you are certain that the oil pressure is
good. If you drive it and pressure is actually low, you will destroy the
engine very quickly. A good replacement will cost at least $2,000, parts
and labor.
*********************

The fact that the light comes on only after the engine warms up is of real
concern, as that is a sign of severely worn main bearings.

If you rev it to 3,000rpm when warm, does the light go off or begin
flickering?

I am unable to find mention of an oil pressure relief valve in my manual,
but on some vehicles, such a valve can stick open, preventing pressure from
building up. This typically happens to neglected engines.

What TeGGeR says - find out what the oil pressure is *really* doing before
driving again. If you don't DIY, have it flatbedded to the shop. It may just
be a bad oil pressure switch, but the stakes are way too high for that
gamble. If you like, you can blindly replace the switch (with a genuine
Acura part) at home and let it warm up, and see what happens. If the light
stays out, all is well. If the light comes on, rely on a professional. Oil
starvation is usually symptomless and is always catastrophic if ignored.

Mike

I have a '91 Integra with an intermittent oil light. I had the oil
sending unit replaced (not Acura part) and it still comes on from time
to time. It is weird, I notice it will come on mostly when the weather
is rainy/wet/damp. Sometimes it will flash on and off for short periods
of time, sometimes it comes on for hours. This has been going on for
about 2 years now. Oil level makes no difference, has come on with oil
full, 1/2qt. low, or 1 qt. low. The car has 243K miles on it and uses 1
qt. of oil every 4K mile oil change. After 2 years I assume the problem
is with the oil sending unit, since the engine runs great, no smoke, no
knocks.................yet.