2013-2018 Nissan Altima cabin air filter replacement

Pull everything out of the glovebox and set it aside. Loose contents will fall out when the box is dropped, and heavy items can flex the door hinge past its stop.

Squeeze the sides of the glovebox inward at the upper corners until the two plastic stops clear the dash pockets. The box will swing down and hang by its lower hinges. On trim levels equipped with a damper strut on the right side, unclip the strut arm from the ball pin so the glovebox can drop the extra inch needed for filter access. A flat-blade screwdriver helps pop the arm off without cracking the plastic socket.

With the glovebox hanging, the HVAC evaporator housing is visible on the passenger side of the dash. The filter access panel is a horizontal plastic door with two small tabs on its left edge. It sits directly above where the glovebox rear wall used to be.

Pinch both retention tabs and slide the cover to the left, then pull it forward and down. The panel is fragile - do not pry from the right side or the tabs will snap and leave the cover rattling every time the blower kicks on.

The filter is a single rectangular pleated element sitting in a shallow tray. Pull it straight out toward the passenger footwell. Expect debris - leaves, pine needles, and occasionally a mouse nest have been pulled from these boxes. Wear gloves. Rodent droppings around the housing require disinfection before installing the new filter.

Vacuum any loose debris out of the filter tray and the exposed section of the evaporator core. Do not force the vacuum nozzle deep into the box - the evaporator fins are thin aluminum and bend at the slightest pressure. Wipe visible mold or mildew off the housing lip with a rag dampened in a mild bleach solution.

The new filter has an airflow arrow printed on the frame. On this platform the arrow points down, toward the floor. Installing the filter upside down cuts filtration efficiency in half and shortens filter life because the pleats collapse against the airflow.

Slide the filter into the tray with the arrow oriented correctly. It should seat flush against the housing wall with no visible gap around the frame. A gap means airflow bypasses the media and dumps unfiltered air onto the evaporator, which is exactly what a clogged filter causes people to notice in the first place.

Fit the right edge of the cover into its slot, then slide the left edge in until both tabs click. Confirm the cover sits flat - a misaligned panel will vibrate at highway speed.

Reconnect the damper strut if it was removed. Lift the glovebox back into position and squeeze the sides inward until the stops re-engage the dash pockets. Open and close the box a few times to confirm it swings freely and latches cleanly.