P0101's in general can be a gremlin from hell.Hmm. Interesting; the FSM only seems to discuss failsafe. However I generally don't look at TSB's unless there's some un-explained gremlin.
When they show up on anything '13 up, the first place to look is TSB's, because half the time there's an ECM repro that fixes it. I dunno if it's Nissan or Hitachi messing up, but they seem to cut the A/F sensor map in the ECM very close in a lot of the newer stuff. The ECM doesn't know the spec is flawed and blames the MAF. Sometimes it doesn't happen for 30K, 50K, even 80K miles until both the MAF and A/F age a little bit. But since the underlying problem is in the A/F map, of course a new MAF won't cure it.