Check engine light is on and codes 0455 and 0449 are showing. i have already changed the gas cap and cleared the codes and the light comes back on. I think it is the purge valve soleniod, but I don't know where the cannister is?
Where is the evac purge valve located on my 2008 GMC acadia. on 2008 GMC Acadia
my suggestion is to stop guessing and have a shop pin point it for you. evap codes are tough to track down and need special equipment to determine the failure.
1 more answer , 1 more comment
Agree with Roy.Evaporative Emission system problems are difficult for anyone to diagnose/test and repair themselves at home. Some evaporative diagnosis requires a scan tool to bi-directionally control solenoids to seal off and open and test for leaks. Another useful tool is a machine that generates an inert gas/smoke that when the system is sealed off, if there are any leaks the smoke "show up" where they are. Also some faults can be intermittent and when the codes are erased the self test procedures your computer uses to test the system can take a week or two to self complete as a certain specific drive procedure has to be performed.