A car air filter cleans the air entering the engine. Signs of a dirty air filter include a misfiring engine, unusual noises, and reduced fuel economy.
8 Signs Your Air Filter Needs Replacing
1. Reduced Fuel Economy.
2. Misfiring Engine.
3. Unusual Engine Sounds.
4. Check Engine Light Comes On.
5. Air Filter Appears Dirty.
6. Reduced Horsepower.
7. Black, Sooty Smoke or Flames Exiting the Exhaust.
8. Smell of Gasoline when Starting the Car.