Code P0017, engine is experiencing rough idle and intermittent shutting off?

The first thing I would do is make sure the engine oil is full and clean. If so, I would swap out the exhaust camshaft oil control valve. Here is the location in the images below.

The OBD-II code P0017 for a 2016 Buick Regal corresponds to a "Crankshaft Position - Exhaust Camshaft Position Correlation (Bank 1)" error. This code indicates that there's a discrepancy between the crankshaft position sensor and the exhaust camshaft position sensor signals on Bank 1 of the engine. This can lead to issues with the timing of the engine's valves.

Check out the images (below). Please let us know how it goes.