1995 GMC Yukon Owner's Manual - Page 307

Air Cleaner To avoid the possibility of un-filtered air being drawn into the engine, make sure the air cleaner coveris on straight and the wing nuts are properly tightened. If there is an arrow on the air cleaner cover, it should point to the front of the engine. Refer to the Maintenance Schedule to determine when to replace the air filter. See "Scheduled Maintenance Services" in the Index. A CAUTION: Operating the engine with the air cleaner can cause you or off others to be burned. Theair cleaner notonly cleans theair, it If stops flameif the engine backfires. 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 off, NOTICE: If the air cleaner off, a backfire can cause damaging engine is a fire. And, dirt can easily get into your engine, which damage will it. Always have the air cleaner in place you're driving. when 6-25