SES, P0128, P0155

[ProfessorX5]

I'm guessing my thermostat is stuck open from the P0128 code (and it was running kind of cool, though I thought that was because of the -40 temps here).

Could the Thermostat be causing the P0155? I've read that it can be a bad 02 sensor, but it could also be an intake leak making it throw this code.

Any clues?

Also, will I damage my car driving it like this? Got 2 more work days before I get a day off to deal with this. Thanks, guys!