Code p0017, bank 1 sensor b error?

Chances are the sensor is okay, and it is the camshaft phaser that is having an issue. I would make sure the engine oil is clean and full with a new filter. Then clear the codes to see if that helps. Here is the location of the camshaft sensor if you want to swap it out which are at the rear of the right-side cylinder head. Check out the images (below). Please let us know what happens.

what would the issue be with the phaser, and how would I check it? I also just changed the water pump and timing chain.

When the phaser starts to wear out or the oil is low or worn out it will not hold its position which will give you the trouble code. @ 190k the phasers probably need replacement.

is there a way to test them?

Yes, they are tested while running, if there are no codes then they are working correctly. Also, some high-end scanner will allow you to move the camshaft position while giving the expected degree of movement. I don't know of a way to check it manually.