Choosing The Right Fuel - Ford 1998 Mustang Owner's Manual

Maintenance and care
2. Carefully turn the filler cap counterclockwise 1/8
of a turn until it stops.
3. Pull to remove the cap from the fuel filler pipe.
4. To install the cap, align the tabs on the cap with
the notches on the filler pipe.
5. Turn the filler cap clockwise 1/8 of a turn until it
stops.
If the "Service Engine Soon/Check Engine" indicator
comes on and stays on when you start the engine,
the fuel filler cap may not be properly installed.
Turn off the engine, remove the fuel filler cap and
reinstall it being careful to align the cap properly.
If you must replace the fuel filler cap, replace
it with a genuine Ford or Motorcraft part. The
customer warranty may be void for any damage
to the fuel tank or fuel system if a genuine
Ford or Motorcraft fuel filler cap is not used.
The fuel system may be under pressure. If
the fuel filler cap is venting vapor or if you
hear a hissing sound, wait until it stops before
completely removing the fuel filler cap. Otherwise,
fuel may spray out and injure you or others.
If you do not use the proper fuel filler cap,
the pressure in the fuel tank can damage
the fuel system or cause it to work improperly in a
collision.

Choosing the right fuel

Use only UNLEADED FUEL. The use of leaded fuel
is prohibited by law and could damage your vehicle.
Do not use gasolines containing methanol. It can
damage critical fuel systems components.
Vehicles certified to meet California emission
standards (indicated on the underhood Vehicle
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