GMC 2001 Savana - Manual (Page 380)

Long Trip/Highway Scheduled Maintenance
7-41
j If Equipped: Inspect Exhaust Gas Recirculation (EGR) system as
described in the service manual.
An Emission Control Service. (See footnote
[.)
j Gasoline Engine Only: Inspect Evaporative Control System. Check all fuel
and vapor lines and hoses for proper hook - up, routing and condition.
Check that the purge valve works properly, if equipped. Replace as needed.
An Emission Control Service. (See footnote
[.)
j Diesel Engine Only: Check the air intake system installation to assure that
gaskets are properly sealed and that all hose connections, fasteners and other
components are tight. Also check to be sure that the air cleaner housing is
properly seated and the cover fits tightly. Tighten connections and fasteners or
replace damaged parts as necessary. This is a Noise Emission Control Service.
Applicable only to vehicles sold in the United States.
j Diesel Engine Only: If your engine has a thermostatically controlled cooling fan,
inspect hoses and ducts for proper hook - up (or every 12 months, whichever
occurs first). Be sure the valve works properly. This is a Noise Emission
Control Service. Applicable only to vehicles sold in the United States.
j Diesel Engine Only: Check the crankcase depression regulator valve system
for any worn, plugged or collapsed hoses. See service manual.
An Emission Control Service.