Lots of Engine Codes Help Please

[whiskeywarden]

I just took my car in for the state inspection and my machanic came back with the following codes:

U31D5
C3000 (this came up 3 times)
PODD6
P17CE
P12CF
PO100 (twice)

I can't find info for any but the last.

Any Help would be greatly appriciated!