a) 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.

b) Or every four years, whichever comes first.

c) Or every five years, whichever comes first. See Cooling System .

d) Or every 10 years, whichever comes first. Inspect for fraying, excessive cracking, or damage; replace, if needed.