Codes P0016, 17 18 19, camshaft sensor

Those codes are not bad sensors as you have discovered. Camshaft to crankshaft correlation codes mean you have worn timing components inside the engine. Namely the timing chains, guides and tensioner(s) are worn and are actually causing the camshafts to be out of time with the crankshaft. Unfortunately this is very common with newer engines because of all of the standards and cost cutting in vehicles. The 3.6 is very well known for this problem because they used a very light chain that wears faster than it should.

Another item which causes these codes on that engine is that the timing wheel they press on the crankshaft can actually move. This will set the same codes as the chains but is harder to check for as you need to remove the oil pan and measure the reluctor wheels position relative to the crankshaft.