Buick 2004 Regal Owner's Manual page 231

To check or replace the engine air cleaner/filter, do the
following:
1. Loosen the screw and clamp on the air duct.
3. Disconnect the duct and reposition it while removing
the cover.
4. Pull out the filter.
5. Inspect or replace the filter if needed.
6. Reinstall the filter.
7. Push the two clips located on top of the filter
assembly to lock the cover.
2. Lift the two clips
located on the top of
the filter assembly
to unlock the cover.
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 helps to
stop flame if the engine backfires. If it is not
there and the engine backfires, you could be
burned. Do not 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
are driving.
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