2005 Cadillac STS Owner's Manual - Page 400

Additional Required Services The following services should be performed at the first maintenance service (I or II) after the indicated miles (kilometers) shown for each item. Service and Miles (Kilometers) Inspect fuel system for damage or leaks. Inspect exhaust system for loose or damaged components. Replace engine air cleaner filter. See Engine Air Cleaner/Filter on page 5-21. An Emission Control Service. For all-wheel-drive vehicles used for trailer towing: Change transfer case fluid. Throttle body service. An Emission Control Service. See footnotes † and (l). Change automatic transmission fluid and filter (severe service). See footnote (h). Replace spark plugs. An Emission Control Service. Engine cooling system service (or every 5 years, whichever occurs first). An Emission Control Service. See footnote (i). Inspect engine accessory drive belt. An Emission Control Service. 6-6 25,000 (41 500 50,000 (83 000 75,000 (125 000 100,000 (166 000 125,000 (207 500 150,000 (240 000