The fuel filter on a 1994 Buick Century is located
on the frame rail, near the fuel tank, typically on the passenger side (right side) of the vehicle. However, the exact location can vary slightly depending on the engine and specific trim level. You'll likely need to get under the car to locate it.
It's usually a cylindrical canister-shaped filter. Because you'll be working with fuel, safety precautions are extremely important. Refer to your owner's manual for detailed instructions and safety warnings before attempting to access or replace it.