Dodge Repair Questions? Ask a Mechanic for Answers ASAP
What is the actual oil pressure as taken with an oil pressure tester?
Well, that's the thing; we should first check the basics, then move on to the codes. By the way, beware of cheap code readers when working on these vehicles - for example U3FFF is not a recognized Jeep code, which might mean your code reader cannot correctly interpret network codes.
OK. Let me know when you have those oil pressure readings and we'll take it from there.
You need to find a way to connect that gauge inline with the OP sensor so any discrepancies can be shown and the truck can be driven - most OBD-II monitors will only execute after the engine is warm and in Close Loop. So far, all we have is that cold-engine reading of 67.5 psi or so, which really doesn't tell us much.
One more thing, trying to diagnose this truck with just a code reader is like trying to fly to the moon on the Wright brothers airplane ;-)
That would be a good starting point. However, going from there without a dealer-level scan tool might not be possible.