There are two kinds of factory air filters in your GM car or truck. One helps keep dirt, debris, and other pollutants from piling up in systems like your air intake's throttle body or carburetor. That's the engine air filter. Another catches most dust and pollen before it can deposit in your heater, AC system, and ventilation ducts. This is the cabin air filter. When both clog, problems arise. If your engine filter blocks, it can enrich your air-to-fuel ratio too much. Engine performance can suffer, your engine can misfire, and your fuel economy can drop. You can even start to see increased emissions. An obstructed cabin filter, on the other hand, cuts the flow of air through your HVAC system. The results are usually interior temp problems and bad air quality. However, a blockage can also put unnecessary stress on your motor. Luckily, it's easy to tell when it's time to change both air filters. Your Check Engine light can let you know something's up. However, it's a safer bet to look for a brittle filter surface, discolored fibers, and accumulated contaminants. Engine filter problems can show in irregular engine noise or producing too much exhaust. Low airflow and unclean odors can indicate cabin filter problems. If you're not clear on when to replace your GM air filters, review your owners manual. It has maintenance schedules that can help. So, which air filters are best for your GM vehicle? You'll want the most reliable you can get. Those are OEM air filters. We've got plenty in stock here at our local auto parts counter. Check out our selection here online, place your order, and save!