Your vehicle has two air filters, and each plays an important role. The engine air filter cleans the air for your vehicle's engine, while the cabin air filter cleans the air that you and your passengers breathe.

They must be changed at least according to the manufacturer's schedule. However, the scheduled maintenance is timed for optimal conditions, so if you have driven under dusty conditions or through harsh winters and road salt, you may need to inspect and change them more frequently.

Inspecting your engine air filter

Your engine air filter cleans the air that your engine uses to burn fuel. If the filter is dirty, impurities may make combustion less efficient. If the filter is dirty enough, gas mileage will be decreased. An extremely dirty filter will cause a vehicle to stop running.

To inspect your engine air filter, you can consult your owner's guide, or look for a plastic rectangular compartment with metal clips on either side. It will be located near the top of the engine.

Older vehicles will have a round metal compartment atop the engine, with a wing nut on top, but most recent vehicles have a rectangular air filter.

When it is located, push the side clips down and out. Lift off the lid, and pull out the filter. If it is dark, and dirt falls out when it is shaken or tapped, then it must be replaced.

You must buy a new one according to the year, manufacturer, and model of your vehicle. They can be found online, in auto parts stores, and in discount stores in limited styles.

Be sure to install it according to the directional arrows on the side. Simply place it in the compartment, and replace the top and side clips.

Inspecting your cabin air filter

This filter removes contaminants from the air that enters your vehicle through the vents. It removes road dust, salt, and allergens that would otherwise build up inside your vehicle. This could cause breathing issues in sensitive individuals.

Inspecting and replacing your cabin air filter is a bit more difficult, because it is close to the interior of the vehicle. Many cabin air filters can be accessed through the glove box, but it must often be removed.

This will entail removing everything from the glove box, pushing the side hinges inward, and unhooking the hydraulic rod (resembling a small storm door closer) from the side of the glove box. 

The glove box will pull out, and you will then look for a small rectangular compartment that is capable of holding a filter the size of a thick book. There will be a small door that can be removed from the front.

Pull out the filter, and if it is dark or dusty, buy a new one using the same methods as the engine air filter.

If you can't remove the glove box, or can't find the either filter compartment, you should take your vehicle to an auto repair shop. It may be more expensive than doing it yourself, but it is absolutely necessary for the health of both you and your vehicle. Contact local shops, like Express Tune & Lube, with any questions.