850 turbo, stalling and not starting, OBD codes

Hello to all! I am new to working on Volvos. I belonged to a different part of this forum a few years back. My 850 had an oil leak so I repaired the Turbo cooler lines after a good deal of effort. I got good info online from a couple of sites and I am appreciative for that.

However, just before I took it apart for the oil fix, it started stalling and would be hard to start. I noticed it would start after flooring the pedal and got me home two times. Now I have finished the oil line repair and while it sits on jacks, I wanted to start it for a leak check. It will fire but not start so I assume it is fuel related.

I ran OBD codes and see PO 442, PO 410, PO 300, PO 301, PO133, PO 103, PO 131, PO 243, and last but not least, PO 172. I almost fell over at the number of fault codes that popped up. The first one above, has shown for a few months and I am thinking it is related to dripping when I fill the gas tank. Is there any other single sensor or part failing that would cause all these read outs? Can it be a loose single wire or vacuum line causing the problem and would it give me this many codes?

I appreciate any and all help or suggestions.