Hi Mike, welcome to Just Answer!.
Overwhelmingly, the most significant code you have is the P0320 (CRANK SENSOR CIRCUIT), but P0381 (possibly 1391) indicates an intermittent crank sensor signal. Sorry, was unable to locate a P1381 code...
Chances are good that it's an actual sensor failure, but the inhospitable environment the sensor and wiring harness live in makes it a definite possibility for your problem.
The engine harness to the crank sensor disappears down the back side of the engine in the engine/ transmission area, just to the rear of the cylinder head. This section of the loom becomes heated by the exhaust manifold and can cause the individual wires of this section to become melted together, sometimes sharing circuits. Oil in the area somewhat complicates matters, softening the individual wire insulation and making a short between wires that much more likely.
The loom also passes over a section of driveshaft, the right side half-shaft which can grind the harness if it comes into contact with it and cause intermittent loss of signal. It's something that needs to be checked in person (of course), because the loom doesn't always drape dangerously like this.
I'd suggest doing some harness "wiggle testing", where the engine is idling and you manipulate any section of harness available to you in a manner that would suggest the vehicle being driven. Push, pull, whatever, but watch carefully for a result that might indicate the harness movements are at fault, then locate the problem based on your actions.
If nothing can be found, I'd suggest simply replacing the senosr, located on the back side of the engine, near #1 cylinder off the crankshaft. Replacement of the cranks sensor connector may be required, depending upon the version presently being used.
Write back if you have any questions.