The problem with the TB wiring in the Versa is that it makes a big, unsupported loop on the last leg into the TB, making it vulnerable to vibration and fatigue. The good part is, failures usually occur right there in the loop where it's easily accessed and repaired. The car is probably throwing the code intermittently, which isn't unusual regardless of the cause. That means the ECM is probably catching an irregularity that's happening too fast for us humans to notice. So it should be safe to drive unless you start seeing symptoms. The first thing to do is make sure the back side (and especially the back edge) of the throttle butterfly is squeaky clean. That's where 90%+ of TB issues happen.