Buick 2002 Century - Manual (Page 256)

6-6
The tethered fuel cap is behind a hinged door on the
driver’s side of your vehicle. While refueling, let the fuel cap hang by the tether
below the fuel fill opening.
To remove the fuel cap, turn it slowly to the left
(counterclockwise). The fuel cap has a spring in it;
if you let go of the cap too soon, it will spring back
to the right.