2006 GMC Yukon Owner's Manual - Page 396

{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 flames 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. 3. Remove the engine air cleaner/filter from the housing. Care should be taken to dislodge as little dirt as possible. 4. Clean the engine air cleaner/filter sealing surfaces and the housing. 5. Inspect or replace the engine air cleaner/filter. 6. Reinstall the cover and tighten the screws. 7. Reset the air filter restriction indicator, if equipped, by pressing the top button on the indicator. Automatic Transmission Fluid When to Check and Change Automatic Transmission Fluid A good time to check your automatic transmission fluid level is when the engine oil is changed. Change the fluid and filter at the intervals listed in Additional Required Services on page 6-6, and be sure to use the transmission fluid listed in Recommended Fluids and Lubricants on page 6-13. 5-22