I had a p0137 on my van a few months ago, and just changed out the upstream O2 sensor, as indicated by the code - problems fixed. But the P2270 references a bunch of possibilites, including the downstream O2, and the PCM. Seems kind of early for this stuff to be happening. How many miles on your 2010? Any other problems in the recent past?
Normally I would say to start by just hanging on an upstream O2, but these sensors apper to have taken a big price jump over my '05. So do you have access to a FSM for the testing specs of these sensors?