newbie lookin for a 6.0 - CEL codes

[jrobie79]

long story short, I've been in the market for a powerstroke for awhile, just waiting for the right opportunity/price/etc...

so I stumbled on a 2006 6.0 single cab 4x4 on craigslist. 180K, went to go check it out today, started it up, seemed to run fine, didn't take it out or anything yet, but the body is in great shape. Check engine light was on and had the guy run it for codes....found these:

P0336 - crankshaft position sensor circuit range
P0341 - camshaft position sensor circuit range
P0677 - Glow Plug Cylinder 7
P2285 - Injector control pressure sensor / circuit low
P2290 - Injector control pressure too low
P2614 - Camshaft position sensor signal output circuit open
P2617 - Crankshaft position sensor signal output circuit open

how serious are these, and are they easy replacements and just worn due to mileage, or is there something underlying which would constitute major repairs?

I am familiar with wrenching on a car, I've change 2 clutches in old BMW's and done complete suspension overhauls on both, so I'm not afraid to do the work myself, just not familiar with diesel engines yet and trying to decide if I should pursue or just ignore it and find something better.

Thanks! hope to learn a lot on here