The MAF sensor is attached to the air filter housing. Do not stretch or bend the wiring to the MAF sensor while replacing the sensor
The air filter is located inside a housing at the left (driver’s) side of the engine compartment.
To remove the air filter on 2009 and earlier models, release the clamp that secures the two halves of the air filter housing together, then separate the cover halves and remove the air filter element
On 2007 through 2009 Expedition/Navigator models, reach under the connector and pull back the retaining clip, then disconnect the connector before pulling up the air filter housing.
2 Release the clamp (A) then separate the housing halves to access the air filter (2009 and earlier models)
On 2010 and later models, loosen the clamp securing the air outlet pipe to the air filter cover, then disconnect the Mass Air Flow (MAF) sensor electrical connector. Release the clamps that secure the two halves of the air cleaner housing, then separate the cover and remove the air filter element
Inspect the outer surface of the filter element. If it is dirty, replace it. If it is only moderately dusty, it can be reused by blowing it clean from the back to the front surface with compressed air. Because it is a pleated paper type filter, it cannot be washed or oiled. If it cannot be cleaned satisfactorily with compressed air, discard and replace it. While the cover is off, be careful not to drop anything down into the housing. Caution:
Never drive the vehicle with the air filter removed. Excessive engine wear could result and backfiring could even cause a fire under the hood
Wipe out the inside of the air filter housing
Place the new filter into the housing, making sure it seats properly
The remainder of installation is the reverse of removal