Well, actually, I do think I might kind of know - I have no storage space in my bathroom, so the pantry-type cabinet in my kitchen has become half-pantry, half-linen closet: the towels are on the top two shelves and the food on the lower shelves.

Still, I haven't had Doritos in the pantry part since I moved in, so it shouldn't really be a Doritos smell... D: