What Causes Unusual Smell In Nose?

I have been smelling exhaust fume odors in my nose for the past two days - it has happened before, although not frequently, but this is the worst episode yet. It s pretty much constant, although stronger at some times than others. My eyes and throat are a little irritated and I feel a little dizzy at times. I have no disorientation or confusion. I wondered about CO in my house but that is unlikely - I have three cats and they would be a whole lot sicker than I am if that were the case. I did scatter mothballs in my cellar to repel insects and can smell it through the furnace vents but it s not extremely strong. I do know that sometimes this is related to GERD. And it could possibly be olfactory phantosmia. I am 58 years old, female, 5 feet 2 inches, smoker, non-drinker, non-drug user, moderately physically active, a few pounds overweight but generally in good health. No history of neurological disease, seizures, Parkinson s etc. Family history of stroke/heart disease (pretty much self-induced via heavy drinking/smoking). This is annoying at best and rather alarming when I think about it for any length of time...any information would be greatly appreciated!