The cabin filter in your vehicle is responsible for filtering the air before it enters the vehicle’s cabin. The cabin air filter catches pollen, dust, dirt and other impurities from the air, keeping the air purified for the vehicle and its passengers. It’s important to keep the cabin air filter clean so when the heater or air conditioner is running, the air being emitted is quality air. The cabin air filter should be replaced every 15,000 to 30,000 miles or as needed.