2012 Grand Caravan - Code P0520

I've been getting a CEL code P0520 recently. I'm not sure what can cause it,
besides the sensor itself having a problem, and I'd like to make sure I'm not
missing something in my work. Here's what I'm seeing:

The Grand Caravan can display the oil pressure. When I first start it cold, the
pressure goes straight to 96PSI, but no higher, ever. It remains at 96 for a
few minutes. After a few minutes, the pressure is lower (low to mid 80s)
when sitting or decelerating, but under acceleration it goes back to 96. After
more time, the PSI when not under load might go as low as 67, and back to
96 under load.

Driving today, the oil temperature was 201F, and coolant was 215F. Recent
history: I changed the spark plugs and one coil boot about 3 weeks ago.
Also, on a mechanic's recommendation, I used Restore brand Engine
Restorer, which I think (wishfully?) helped smooth the engine out somewhat.
I changed the oil yesterday and reset the code, but now it's back.

I suppose it's possible I need to just let the oil run through the engine more.
Or maybe I need to replace the sensor. Or something else, maybe? I thought
oil pressure was supposed to be under 60PSI or so. Any suggestions on
narrowing this down?

Update: Another source says that on a 3.6 Pentastar, the oil pressure can go
up to 130PSI. That moves me in the direction of replacing the oil pressure
sensor. Since the pressure climbs very quickly to 96PSI but will not go a
single PSI beyond it, I think it's failing to measure correctly.