Cadillac 2000 Catera Owner's Manual page 261

To reinstall the air cleaner assembly, place the air filter in
the air cleaner lid, then insert the lid and filter together
into the housing. Reattach the five clips, reinstall the air
intake tube and tighten the clamp. Return the coolant
surge tank hose to its proper position.
Refer to the Maintenance Schedule to determine when to
replace the air filter.
See "Scheduled Maintenance Services" in the
Maintenance Schedule booklet.
CAUTION:
Operating the engine with the air cleaner/filter
off can cause you or others to be burned. The
air cleaner not only cleans the air, it stops flame
if the engine backfires. If it isn't there, and the
engine backfires, you could be burned. Don't
drive with it off, and be careful working on the
engine with the air cleaner/filter off.
NOTICE:
If the air cleaner/filter is off, a backfire can
cause a damaging engine fire. And, dirt can
easily get into your engine, which will damage it.
Always have the air cleaner/filter in place when
you're driving.
Passenger Compartment Air
Filter Replacement
The passenger compartment air filter traps most
of the pollen from the air entering your vehicle.
Like your vehicle's air cleaner filter, it may need to
be changed periodically. For how often to change the
passenger compartment air filter, see your Maintenance
Schedule booklet.
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