Pontiac 2002 Firebird - Manual (Page 252)

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The fuel cap is located behind a hinged door on the
driver’s side of your vehicle. While refueling, allow the fuel cap to hang by the tether.
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.