How often should engine air filter be changed?
You should change the air filters at least once a year or every 12,000-15,000 miles, whichever comes first. If you drive in dusty/dirty conditions, you may be required to change your filter more often. Some filters are marked with a service life indicator that changes color when it's time to be replaced.
1. You have a hard time starting car.
2. Misfire or rough idle.
3. Vehicle stalling.
4. Fuel system component failure.
5. Loud noises from the fuel pump.