2011 Chevrolet Tahoe Owner's Manual - Page 496

11-6 . Service and Maintenance First Engine Oil Change After Every 160 000 km/100,000 Miles . . Evaporative control system inspection. Check all fuel and vapor lines and hoses for proper hook‐up, routing, and condition. Check that the purge valve, if the vehicle has one, works properly. Replace as needed. An Emission Control Service. The U.S. Environmental Protection Agency or the California Air Resources Board has determined that the failure to perform this maintenance item will not nullify the emission warranty or limit recall liability prior to the completion of the vehicle's useful life. We, however, urge that all recommended maintenance services be performed at the indicated intervals and the maintenance be recorded. Automatic transmission fluid change (normal service). See Automatic Transmission Fluid on page 10‑12. Four‐wheel drive only: Transfer case fluid change (normal service). Check vent hose at transfer case for kinks and proper installation. Check to be sure vent hose is unobstructed, clear, and free of debris. During any maintenance, if a power washer is used to clean mud and dirt from the underbody, care should be taken to not directly spray the transfer case output seals. High pressure water can overcome the seals and contaminate the transfer case fluid. Contaminated fluid will decrease the life of the transfer case and should be replaced. Spark plug replacement and spark plug wires inspection. An Emission Control Service. First Engine Oil Change After Every 240 000 km/150,000 Miles . . Engine cooling system drain, flush, and refill (or every five years, whichever occurs first). See Engine Coolant on page 10‑17. An Emission Control Service. Engine drive belts inspection for fraying, excessive cracks, or obvious damage (or every 10 years, whichever occurs first). Replace, if needed. .