|I have had the same problem of smelling exhaust fumes when I breathe for the last week. I am getting headaches and am nauseated because of it. I saw my physician yesterday. He told me that the most common cause of the exhaust smell is from GERD (gastroesophageal reflux disease). It is especially severe when combined with sleep apnea. He said that the smell is stronger when I am relaxed and doing things like reading, sitting at the computer, sleeping, etc because I am taking shallower breaths through my nose with my mouth closed. This allows the "exhaust" concentration to be stronger. I have noticed that it isn't as strong when I am talking or walking around doing things. He suggested a scope to check the esophagus and may require a biopsy and surgery. I'm wondering if the antibiotics that I took for the last 10 days contributed to this because I was struggling with reflux while I was taking them. I think I will wait for a couple of weeks to see if it goes away before I continue with tests.
He also said that it could be problems with my gallbladder and it's effect on my liver. This would require an ultrasound. However, I didn't feel any pain when he pressed on my gallbladder and my blood tests did not show any irregularities with my liver so he figured it was probably the GERD issue. If I hadn't discovered that other people were experiencing the same problem, I don't know that I would have gone to see my doctor. Thanks everyone!