My truck has been acting wierd for a few weeks now, surging shortly after starting (hot or cold start) and dieing on occasions. But it didn't always do it, 90% of the time it run smooth. It always started right back up until recently. I would kill it and go into store and come back out and it would not start but after 10-15 min of trying to start it she would finally fire up. I have the following codes. P0016 P0344 P0456. I know what the codes are, but would like for someone to advise me where to start at. I have already bought a cam and crank sensor. All input and help is greatly appreciated! sorry for the long post.

2003 Ram 1500 4X4 4.7L Auto