Getting codes 998 and 122.

That's not a MAP, it's a BAP. Does the same thing but doesn't reference manifold, only references barometric pressure (to adjust for altitude changes).

0.051v yes you should get a code. You may want to double and triple check that though. Also check for VREF, you should see roughly 5v on the orange/white wire. I don't like to ground the other lead of the DVOM, I like to use the signal ground from the computer, which is the black/white wire.

Your readings are odd. 0.051v is very low, as is 0.124. Check your grounds. There are quite a few of them; and one important one near the computer.