When I drive my car even a short distance (1-3 miles) and I turn the heater on within a minute I can smell a burning rubber smell. When I turn off the heater I cant smell it, just a very faint smell of it. Also, it does not smell under the hood, only when inside the car. finally, the catalytic converter cover came off but that was months ago and it just started this smell now. Any suggestions as to what it might be???