Buick Verano Owner's Manual page 326

11-6 Service and Maintenance
Footnotes — Maintenance
Schedule Additional Required
Services — Normal
(1) Or every two years, whichever
comes first. More frequent
replacement may be needed if the
vehicle is driven in areas with heavy
traffic, areas with poor air quality,
or areas with high dust levels.
Replacement may also be needed if
there is a reduction in air flow,
excessive window fogging, or odors.
(2) 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.
(3) Or every four years, whichever
comes first.
(4) Or every five years, whichever
comes first. See Cooling System on
page 10 14.
(5) Or every 10 years, whichever
comes first.
(6) Inspect for fraying, excessive
cracking, or damage; replace,
if needed.