Hummer 2003 H2 Owner's Manual page 352

2. Pull the air cleaner/filter up and out from the
housing. Care should be taken to dislodge as little
dirt as possible.
3. Clean the filter sealing surface and the housing.
4. Install the new engine air cleaner/filter.
5. Reinstall the cover and tighten the screws.
Refer to the Maintenance Schedule to determine when to
replace the engine air cleaner/filter. See "Owner Checks
and Services" in the Index.
6-18
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.