Chevrolet MONTE CARLO 1998 Manual page 228

To remove the cap, turn it slowly to the left
(counterclockwise). The cap has a spring in it; if you let
go of the cap too soon, it will spring back to the right.
If you get gasoline on yourself and then
something ignites it, you could be badly burned,
Gasoline can spray out on you if you open the
fuel filler cap too quickly. This spray can happen
if your tank is nearly full, and is more likely in
hot weather. Open the fuel filler cap slowly and
wait for any "hiss" noise to stop. Then unscrew
the cap all the way.
Be careful not to spill gasoline. Clean gasoline from
painted surfaces as soon as possible. See "Cleaning the
Outside of Your Vehicle" in the Index.
When you put the cap back on, turn it to the right
(clockwise) until you hear a clicking sound. Make
sure you fully install the cap. The diagnostic system
can determine if the fuel cap has been left off or
improperly installed. This would allow fuel to evaporate
into the atmosphere. See "Malfunction Indicator Lamp"
in the Index.
NOTICE:
If you need a new cap, be sure to get the right
type. Your dealer can get one for you. If you get
the wrong type, it may not fit properly. This may
cause your malfunction indicator lamp to light
and your fuel tank and emissions system
may
be
damaged, See "Malfunction Indicator Lamp" in
the Index.
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