Raw nuts in their shell do not require Passover certification.
Shelled raw nuts that list BHA, BHT, or any other additive on the ingredient label require special Passover certification. If no additives are listed, raw nuts may be acceptable when bearing an OU symbol. Pecans that are whole or half are acceptable with an OU certification, midgets and pecan pieces require Passover certification. (See Almond Meal)
Peanuts:
In Europe different communities had different customs about peanuts. Some considered them to be kitniyot; while others ate peanuts on Passover.
Many years ago the OU certified Kosher for Passover peanut oils for those Jews whose custom was to eat peanuts and peanut oil on Passover.
However, in recent years we have stopped certifying peanut oil as Kosher for Passover.
Furthermore, we cannot recommend that people whose custom is to use peanut oil on Passover use un-certified peanut oil, because of concerns about the peanut oil being processed on non-Passover equipment.
