Chevrolet Optra 2004 Owner's Manual page 132

3. Remove the old passenger compartment air filter.
4. Then reverse the steps to install the new air filter.
Ensure that the new filter is inserted to the correct
air flow.
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Warning Lights, Gages, and
Indicators
This part describes the warning lights and gages that
may be on your vehicle. The pictures will help you
locate them.
Warning lights and gages can signal that something is
wrong before it becomes serious enough to cause
an expensive repair or replacement. Paying attention to
your warning lights and gages could also save you
or others from injury.