Asking for a friend, ever since she has had the car there is a sweet smelling smoke that comes out of the passenger side vents. It happens with and without the AC on. Also happens when using defrost. Any ideas on what it could be and how to fix it would be greatly appreciated.

 

Sounds like a leaking heater core, the sweet smell is antifreeze.

 

Replacing the heater core on some models is not too bad, and if the dash needs to be disassembled to remove it , it can become quite a job.