GMC Denali 2004 Owner's Manual page 413

Service
Replace spark plugs and inspect spark
plug wires. 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.
Additional Required Services (cont'd)
25,000
(41 500) (83 000)
50,000 75,000
(125 000) (166 000)
100,000 125,000
(207 500)
•
150,000
(240 000)
•
•
6-7