1999 Buick Regal Owner's Manual - Page 258

yellowblue Engine Air Cleaner/Filter The engine air cleaner/filter is located underneath a diagonal brace on the driver's side of the engine. To check or replace the air filter: See "Scheduled Maintenance Services" in the Index. 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. 1. Loosen the wing nut on the air duct and lift up on the two clips located on the top of the filter assembly. 1. Then disconnect the duct and reposition it while removing the side cover. 2. Pull out the filter. Be sure to install the air filter and install the cover tightly when you are finished. 3. Replace the filter if needed. Refer to the Maintenance Schedule to determine when to replace the air filter. 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. 6-18