An improved engine performance is the outcome of an effective mixture of fuel and air. The fuel is supplied by the fuel system while the air is handled by the air intake system. The air intake system delivers fresh air to the engine of your Nissan Altima. However, most of the time, the air that is collected contains unnecessary particles that may affect the efficiency of the fuel/air mixture. In order to decontaminate the air, a specially-designed air filter is applied. As the name implies, the air filter filters the air that gets into the engine. Decontaminating the air is vital to guarantee the efficiency of the mixture and the engine’s operating efficiency. Remember that if the fuel and air has been efficiently fused, it will provide sufficient energy to your Nissan Altima. The air filter is a vital component of every air intake system. Do you want to enhance the performance of the air intake as well as the engine of your auto? Then, you should choose a superior quality K&N Air Filter. This air filter is made of premium cotton gauze material that is slotted in an aluminum wire mesh. The material provides longevity to the filter. The K333320312 K&N Air Filter is the most fitting air filter for your 1999-2001 Nissan Altima. Visit and explore our online site to come across our broad selection of K&N Air Filter that will fit your Nissan Altima and other non-Nissan models. And for all your other driving needs, we also offer auto parts and accessories from the leading brands in the industry.