spark plugs GMC YUKON XL DENALI 2004 Owners Manual

Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that will help
prevent engine and fuel system deposits from forming,
allowing your emission control system to work
properly. You should not have to add anything to your
fuel. However, some gasolines contain only the
minimum amount of additive required to meet U.S.
Environmental Protection Agency regulations. General
Motors recommends that you buy gasolines that
are advertised to help keep fuel injectors and intake
valves clean. If your vehicle experiences problems due
to dirty injectors or valves, try a different brand of
gasoline.
Gasolines containing oxygenates, such as ethers and
ethanol, and reformulated gasolines may be available in
your area to contribute to clean air. General Motors
recommends that you use these gasolines, particularly if
they comply with the speci®cations described earlier.
Notice:Your vehicle was not designed for fuel that
contains methanol. Do not use fuel containing
methanol. It can corrode metal parts in your fuel
system and also damage the plastic and rubber
parts. That damage would not be covered under
your warranty.
Some gasolines that are not reformulated for low
emissions may contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. General Motors does
not recommend the use of such gasolines. Fuels
containing MMT can reduce the life of spark plugs and
the performance of the emission control system may
be affected. The malfunction indicator lamp may turn on.
If this occurs, return to your authorized GM dealer for
service.
5-6

Additional Required Services (cont'd)
Service25,000
(41 500)50,000
(83 000)75,000
(125 000)100,000
(166 000)125,000
(207 500)150,000
(240 000)
Change automatic transmission
¯uid and ®lter (normal service).·
Inspect evaporative control system.
An Emission Control Service.
See footnotes ² and (g).···
Replace spark plugs and inspect
spark plug wires.
An Emission
Control Service.·
Engine cooling system service
(or every 5 years, whichever occurs
®rst).
An Emission Control Service.
See footnote (i).·
Inspect engine accessory drive belt.
An Emission Control Service.·
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Normal Maintenance Replacement Parts
Replacement parts identi®ed below by name, part number, or speci®cation can be obtained from your dealer .
Part GM Part Number AC-Delco Part Number
Oil Filter 25010633 PF44
Engine Air Cleaner/Filter 25313349 A1518C
Spark Plugs 12571164 41±985
Fuel Filter 25121792 GF626
Front Wiper Blade Part Number 15153642 Ð
Front Wiper Blade Type ITTA ITTA
Front Wiper Blade Length 22.0 inches (56.0 cm) 22.0 inches (56.0 cm)
Rear Wiper Blade Part Number 22121329 Ð
Rear Wiper Blade Type ITTA ITTA
Rear Wiper Blade Length 14.0 inches (35.0 cm) 14.0 inches (35.0 cm)
6-15