If you mean "cabin air filter," there is not one on the 1997 Ford Expedition. I have a '97 Expedition Eddie Baur and have looked and researched thoroughly.
You don't fix it, you just replace it.
The AC filter, also known as the cabin air filter, in a 1997 Ford Expedition is typically located behind the glove compartment. To access it, you may need to remove the glove compartment door by unscrewing screws or releasing clips. Once the glove compartment is out of the way, you should see the filter housing, which can be opened to replace the filter.
The fuel filter on the 1997 expedition is under the drivers side under- carrige. You will need a special tool to remove the filter. The special tool runs about 6 bucks and the filter around 10. Could be a tedious job but overall a easy.
Check your owners manual. If you don't have one copy & paste this link. http://www.genuineservice.com/genuineservice/en/gloveboxresults
According to the 1997 Ford Expedition Owner Guide : Both the 4.6L and the 5.4L V8 engines take the : ( Motorcraft FL-820-S engine oil filter )
take the axle out
On a 1997 or 1998 Ford Expedition ( 5W-30 ) * with engine oil filter change , 5.7 liters / 6.0 U.S. quarts
it is under front bumper on drivers side...this is on a 1997 expedition 4x4
You don't it is a paper filter, you replace it.
It doesn't have a cabin filter.
Only to replace it with a new one
Very carefully