Mine started with the same codes soon after I got it. I found vacuum leaks around my fuel injectors. I could hear it sucking and could almost stop it when I moved the fuel rail around (Loosened the bolts that hold it a bit). I replaced the 'O' rings and problem solved for about 4 months, but now it's back again.
At this point mine goes off every few weeks, for a day or two, then right back on (Usually when slowing down or coming to a stop), so I think it's O.K. while driving?

Looks like we're in the same boat, I've just been ignoring it while the weather is freezing cold (which might be part of the problem?????).