Summary: There's a good chance a restrictive paper air filter is housed in your air box. The amount of air restriction caused by an air filter is directly related to engine performance and gas mileage. Paper air filters, one of the cheapest components in your car, are a win-win for automotive service centers -- cheap to supply, and a great way to bill for service - but a lose-lose for you, the consumer, because you are the one who is paying to keep replacing them.
