Air Filtration: There are two major air filtration systems on your vehicle. One cleans the air that enters the cabin of your vehicle. The other allows air into the combustion chamber of your engine. A clogged air filter may force your engine to consume more fuel than it normally would. It may even prove difficult to start. A clogged cabin filter could result in noxious fumes entering the cabin of your car or it may cause your air conditioning system to overwork itself.