Lexus, the luxury line-up of cars associated with Toyota, released the IS series in 2001. The initial model vehicle released, known as the IS300, came fitted with a 3.0-litre, in-line four-cylinder engine that produced 215 horsepower and 218 foot-pounds of torque. In 2006, Lexus dropped the "300" moniker in favour of a wider IS line-up that included the IS250 and the IS350 that came equipped with a 204-horsepower, 2.5-litre V-6 and a 306-horsepower, 3.5-litre V-6, respectively. The IS250 came standard with air conditioning and a cabin air filter to keep dust and pollen from the outside air from reaching the cabin. Lexus recommends cleaning the cabin air filter every 15,000 miles and replacing it every 30,000 miles.
Turn the vehicle's ignition to the "Run" position, but do not start the engine.
Turn your IS250's air-conditioning system to the "Recirculating air" setting -- it is not possible to remove the filter with the air conditioning set on "Outdoor air."
Turn the vehicle's ignition to the "Off" position.
Open the glove box and locate the roughly 7-by-3-inch plastic cover at the rear of the glove box, known as the glove box partition. Pull the glove box partition upward to release it, then pull it out of the glove box. This exposes the cabin air filter cover, located directly behind the partition.
Press the tabs on both sides of the cabin air filter cover and pull the cover toward you to remove it. Notice the felt-like filter behind the cover.
Pull the filter from the glove box.
Insert the new cabin air filter, with the "Flow" arrow facing downward, into the slot at the rear of the glove box.
Reinstall the cabin air filter cover by pressing it until the tabs lock into place.
Place the glove box partition over the slot on the rear of the glove box; make certain to line up the tabs on the partition with the notches in the glove box. Push down on the partition to lock it into place.
Close the glove box.