02 dodge dakota 4.7l v8 code P0340

Really need some help here. I have a 2002 dodge Dakota 4.7l v8 and the other day it would crank but it wouldn't start so I plugged in my obd2 reader and it was showing a code P0340 and P1391. My obd2 reader said the 1391 code was model specific and didn't give details on what it was but the 340 code was for the camshaft position sensor. The first thing I did was check the wiring and a previous owner did a hackjob on the wires and were covered in oil from a valve cover gasket leak. I cleaned off the wires and plug and plugged it back it and it started right up. The next we were driving around town and as I was making a turn and the engine just shut off and I tried to start it back up and it would start but shut down immediately. I gave it some gas right when it started and it stayed running. I decided to take it back home and it did the same thing 2 more times on the way home which was only about half a mile. I figured it was the hackjob wiring the guy did so I got a new plug and wired it in. Still got the 340 code so I got a new sensor, even though the one that was in it had obviously been replaced already, and put it in. It started but took about 6 cranks for it to finally turn over, and I didn't like that. Still got the 340 code so I thought maybe the crankshaft sensor might be dirty. That too had already been replaced but I took it out and looked at it and it seemed fine same with the wiring and plug, so I cleaned it off and put it back in. Now when I try to start it, it cranks over but dies immediately and even giving it gas doesn't keep it running. It'll rev up but dies. I'll replace the sensor today, but like I said its already been replaced. I also have a code p0455 for an evap leak (large) and p0450 for evap below efficiency threshold bank 1 but I've been dealing with that since we bought it. Replaced a broken hose and both 02 sensors but I guess there is another leak somewhere. Not sure if those are related in any way. Can anyone help me out with this? I'm no professional mechanic just some basic knowledge on bits and pieces. Any help or advice would be greatly appreciated.