Here's where things stand with the issue.

I inspected the vacuum lines (AIR, EGR, Line to dash, etc.) and found a slight leak in the fuel pressure regulator. Once done, the engine ran worse, sputtering along with surging and black smoke from exhaust. I looked into the EVAP SOV and noticed that the engine ran better with the line from the manifold being plugged (I did get PIN8 code 36 before this). Also changed sparks and connectors at each coil (all sparks caked with dry soot)

So now the with the EVAP SOVplugged at vacuum and fault codes reset, here are the flash codes that surface after a 15 minute highway trip to work.

DM code 3

Pin8 Code 9 – O2S (Bef. TWC) –voltage too high circuit open or vltg implausible.
Code 13 Lambda cntrl sys at rich or lean limit.
Pin14 No Faults

Is it possible that I fixed or worked around initial vacuum leaks but my O2S got trashed in the process?

Thanks,
Geoff