2004 Buick 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. 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. 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. 5-23