Diesel engine oil pressure 06 powerstroke 6.0

Is this a diesel or gas vehicle ? and what engine does it have ? They all have different type of systems . Diesels have a low pressure and high pressure pump and IPC and IPR valves . Gas vehicles have different controls ,( FPDM ) fuel pump driver module that is controlled by the engine computer ,with the help of a fuel rail pressure sensor. There is problem with the FPDM because of it's location under the vehicle . How To Fix the P1233 FPDM No Start Condition DTC Ford Truck Technical... 06 Ford Powerstroke diesel no start low injection pressure icp ipr

it appears that the pump pressure relief valve is stuck and is not sealing off the oil system to allow pressure to build up at idle. It may be necessary to remove the oil pump and pressure relief valve for checks /repairs.

I looked at info for 1500--5.7L engine.
6 psi @ 1000 rpms
18 psi@2000 rpms
24 psi @ 4000 rpms

Sometimes, you can use analog gage in place of oil pressure sending unit and double check oil pressure that way. If oil pressure is actually low, if high mileage engine, I doubt replacing oil pump will help. I just wanted to add, check oil pressure engine warmed up.

Well if you trust the gauge, the problem could be the pump or several other components. If the crank bearings are worn out, you will loose oil pressure as the engine warms up just as you would with a weak pump.
You won't know until you take the oil pan off and inspect.

Have the oil pressure checked with a special test tool, you may have a defective oil pressure sending unit. If the pressure is low then you have other more serious problems and the truck should not be driven until the oil pressure issue is resolved, low pressure will destroy the engine if left unrepaired.

You need to pull the pressure sensor and install a manual test gage, (borrow from Autozone or other chain part store) that is the only way to verify the engine is not loosing oil pressure.

Usually on idle (warm engine) this is OK.

When you had the pump replaced did anyone look at the rod and main bearings? 99% of all low oil pressure problems I've seen has been directly related to bearing wear, not a bad oil pump.
Replacing the pump will give you slightly better pressure temporarily but that won't last very long.
Verify the actual oil pressure using an external mechanical gauge. If it's low (likely it is) go back into the oil pan and use plasti-gage on the bearings to measure clearances.
In reality though, in an engine with that many miles, it's best to either completely rebuild or replace it though.

check oil pressure sensor on strokers need a good oil pressure before they wold start and if they lose it , it would turn off the engine

Check you IAC Idle air control valve, check your EGR valve. If both check out ok. Then make sure that the glow plugs are glowing properly if this is diesel, if this is gas check altornator and spark plugs.