How can I cheat the Idle up? I'm getting a low oil pressure light at Idle, 800 RPM. I would like to increase the Idle to 1000 to keep from getting the light.

Totally wrong headed thinking,
what is correct, is measure the real pressure,
if wrong, then engine is doomed, fibbing to self and gauges, is over that top.
the IDLE SPEED is fixed in the PCM< , its no CARB
now since 1988, so, a wasted talking them.
if the pressure is low, what is your oil, 10w-30 , or 10w-40?
try this oil
or try a new oil sender some come on at 3psi.
so you thing having 2psi is good for your engine?
why not ask your mechanic to check the oil pressure,
and let truth win your life, and not try to hide real problems.\

lets do the list. its not hard, ever..
1: sender bad. (use a real gauge and win)
2; running 0w oil in a high mileage engine. you never said miles.
3: bad engine bearings. tops the list, crank or rod. the head has a oil restrictor there preventing a blown head from wrecking crank journals and there bearing shells.
4: bad pump, I BET NOT.
5: a defective oil filter, in that its clogged and the bypass is jammmed (bad) double dead. this.
6: low oil levels.
7: coolant in the oil. looks like milk.
8: gas in the oil, oil looks like water, and smells like raw gas.
9: some dork in Jiphpyboobs, put the wrong fluid in the engine.
can be anything there, due to nincompoop..status.....and such...
what we do is believe its real then prove other wise.
using TOOLS.

That wont work trying to adjust idle can be done on older cars with a carburetor or the older throttle bodies new vehicles trying to do it will set off check engine lights on most sensors sound more like oil worn out---oil filter or pump problem change oil and filter and do a flush ---and put in an additive such as lukas - royal purple etc---also why did head need replacing was oil pump tested