The cabin air filter removes airborne contaminants before they enter the car's interior through the heating and cooling system. The filter keeps the cabin clean, makes the ride more pleasant and reduces allergy problems.
The cabin air filter is often found behind the glove box on new vehicles. The filter on other vehicles is either under the hood or under the dashboard. The filter traps airborne contaminants, dust, pollen, fumes and small pieces of debris.
If the cabin air filter becomes clogged, it can no longer remove the contaminants from the air. The car may smell musty, and the heating and cooling system may have a reduced air flow.