Editor’s Note: In this limited series, Under the Hood, we’ll share do-it-yourself tips for drivers who want to wrench their own cars, no matter their skill level.
What’s one thing you and your car have in common? You both need to breathe. While engines don’t have lungs, they do require a steady supply of air to power the combustion that keeps them running. Modern cars “breathe” through an intake system that features an air filter, which catches dirt and dust before it enters the motor, where it can cause damage. As you might imagine, over time, the filter gets dirty. Changing the filter will promote better airflow into your engine and keep it clean–and it’s one of the simplest automotive maintenance jobs you can do. When you change yours, it’s a prime opportunity to check your vehicle’s hoses and belts for wear.
Locate Your Air Filter and Remove the Cover

First, grab your car’s owner’s manual and pop the hood of your vehicle. Consult the manual to find the air filter assembly in the engine bay. The location will vary between vehicles, but it’s likely a large plastic box with a large-diameter hose extending from it and into the engine. Undo the plastic clips or loosen the screws that secure the cover. You might also need to unlatch the hose or unplug some wiring to remove the cover and access the filter. (Pro tip: before removing any components or hardware, take a picture of the air filter area so you can later put it back together to match the pic.)
Assess Its Condition and Replace

(Purchase the following supplies from eBay Motors or your retailer of choice.)
Once you’ve removed the cover, you should be able to see the air filter itself. Remove it and hold it up to a bright light to assess its condition. If it’s covered in a heavy layer of dirt and light doesn’t pass through easily, it’s time to replace it with a new one.
You can opt for a paper filter (the cheaper option) or a reusable one that you clean at set intervals (pricier but creates less waste). Whichever you choose, make sure you purchase one that will fit your specific car–auto part shops, and most online marketplaces will provide a way to search for the exact part you need. Put the new filter into the air filter housing, making sure you place the correct side facing down. Then replace the cover, use the screws or clips to secure it, and reattach any hoses or wiring you unplugged. Your new air filter is now installed, and your engine can breathe easier once more.