1998 Cadillac Catera Owner's Manual - Page 255

The cap is behind a hinged door on the passenger's side of your vehicle. To use this feature, your vehicle must be in PARK (P). Press the FUEL DOOR unlock button located on the instrument panel center console to unlock and open the fuel door. A You can also press the fuel button on the remote keyless entry transmitter to access the fuel cap. Your vehicle may or may not have a tethered cap. fuel Hang the fuelcap inside the fuel door as shown by the arrow. To remove the cap, turn slowly to the left it (counterclockwise). The cap has a spring init; if you let go of the cap too soon, it will spring back to the right.