1998 Buick Park Avenue Owner's Manual - Page 293

Operating the engine with the air cleaner off can cause you or others to be burned. The air eleaner not only cleans the air, it stops flameif the engine it backfires. 1% isn't there, and the engine backfires, you could be burned. Don't drive with engine with it off, and be careful working on %he the air cleaner off. If the air cleaner is off, a backfire can cause a damaging enginefire. And, dirt cars easily get into your engine, which will damage it. Always have the air cleaner in place when you're driving.