Smelling odors, that aren't really present is a smell sense disorder, known as phantosmia.
Usually, this symptom is due to some damage of smell sense receptors or brain damage.
This can follow some viral infection, like flu, cold, chronic sinusitis, nose surgery or trauma, and, exposure to certain toxins and drugs.
This can be seen as a preceding symptom in migraine headache sufferers, or accompanying symptom of seizures (epilepsy).
Sometimes, more serious condition can be hidden, like, brain tumor, or brain injury, so, this problem needs detailed evaluation.

I have the same thing. I don't know what it is. Whenever I drink coffee I get this smell in my nose - and it stays there - I can feel it in the back of my throat too. I stopped drinking coffee and it went away, but it sill happens some time. - what's wrong? it happens when I smell burning too.

I am just recovering from a migraine from hell, normally i can sleep them off but this time i actually thought i was going have to ring an ambulance, i went to sleep to try and get rid of it, but at 3am it woke me violently, i managed to doze sat up on the settee, it has taken me a further 24hrs to get over this....since the onset of my migraine i have had the awful smell of bonfire smoke in my nose, everywhere i go outside...nobody else can smell it! I am going the drs on friday so i may ask then. My mum suffered an anyurism and survived, i do remember her saying just before she collapsed she had had this awful smell which is the last thing she remembers!