I have a 09 chevrolet silverado1500 crew cab. My check engine light stays on with code p0449. Do i need to change the evap solenoid or the charcoal canister? Or both?

 

Your 09' truck should still be under Factory warranty because the problem is emissions related.

Go to the Dealer....some parts of the emissions go past the 100K warranty I believe also.

 

I have a 2006 and its the canister. They made a new part which reroutes a new part (vent) around the tranny. The replacement costs 167. Well on the 2006 tahoe the part stayed the same and dont require them to reroute it. So i called gmpartsdirect spoke to paul and ordered the canister for 17$ for the 06 tahoe and it was exactly the same as the one on my truck. I changed it myself in 20 min and saved hundreds.

You can also take yours out and clean it out. It is likely full of dust.