Low oil Pressure after timing chain guide replace

History:

1. Vehicle has been running slightly hot for about two years. On occasion the A/C would shut off (I assume as a safety mechanism). Our mechanic could not tell us why, every time we brought it in, they would just add oil.

2. Then the car’s main timing chain guide broke and was making quite a bit of noise.
3. I opened the timing chain cover and replaced the water pump, all three timing chains, the main guide and the guide on the right. I purchased new timing chains so that I could see the timing marks. (I wanted to make sure it went back correctly in case it skipped) I replaced the main timing chain tension-er and the guides on each of the secondary timing chain tension-er's, and coolant temperature sensor. I replaced the radiator. I used a no spill funnel to remove the air from the coolant system.

I noticed that inside the timing chain case there was a buildup of dried oil in spots.
I replace the thermostat and the spark plugs.

4. The car started right up, but indicated low oil pressure after warm-up and makes a noise when it is warm and I hit the gas along with a loss of power. Additionally, it tends to run slightly hot but does not seem to overheat like it did prior to the guide breaking. After I put it back together I was getting the check engine codes (p0011 and p0021), which I understand might be triggered by a low pressure situation.

Things done to diagnose:
1. Pressure tested coolant system with car running and off (to see if there was a head gasket leak- it seemed to hold the pressure.
2. I re-seated the oil pressure sensor and cleaned the connections.
3. I replaced the oil cooler seal (it was leaking slightly) I cleaned around the area and was looking for a relief valve but could not find it.
4. I changed out the cam seals (I did not do that the first time).
5. I replaced the oil filter three times (the last time with an OEM filter.
6. I tested the oil pressure when I first start the car at idle of 1,000 rpm it is 40 psi and 40-55 psi @ 2,000 rpm.
after warm up
only 3 PSI @ 1,200 rpm and 5 PSI @ 2,000 rpm and noise when I hit the gas and a loss of power.

Things I suspect
1. *Oil gallery gasket failure (dried oil I the timing case).
2. Oil pump failure.
3. Clogged oil passageway.
4. Stuck or failed oil pressure relief valve behind oil cooler.
5. Stuck or failed oil pressure relief valve somewhere else (oil pump?).
6. I may have hooked a hose back up incorrectly (I do not think so, but it is always possible).
7. Timing off (I think it would run really poorly, which is not the case).
8. Bad replacement part (even though all of the timing chain components were OEM).
9. Head gasket failure (slight milky look around cap, but oil looks fine (coolant pressure test did not show a leak/ the car has been sitting so I think it just might be moisture in the system.

With the exception of number one, I am not sure why the pressure would only drop after warm up.

Things that confuse me
1. This is my wife’s car and she does not remember the gauge on the oil pressure dropping.

Tests I can still perform:
1. I purchased a leak-down tester

What do I do next? Opening up the timing case again is quite a bit of work.