It might be nothing if it is still in the normal zone. I had a mustang like that and nothing was wrong with it.
If you are still concerned, take it to your Nissan dealer and make sure whatever the problem is is fixed correctly.
It is still under warranty until 36,000 miles.
Bad oil sensor or bad oil pump, I would think it is the oil sensor.
References :
Mechanic
It might be nothing if it is still in the normal zone. I had a mustang like that and nothing was wrong with it.
If you are still concerned, take it to your Nissan dealer and make sure whatever the problem is is fixed correctly.
It is still under warranty until 36,000 miles.
References :
your cool the vehicle uses oil pressure for valve timing control so it will go up and down as rpm goes up so will oil pressure
References :
nissan tech