What is the p0449 code for the chevy avalanche?

Code p0449 in a Chevy Avalanche means the system has detected an evaporative system leak. This means something is wrong with the EVAP canister, also called the purge valve. The valve contained charcoal which filters and absorbs fuel emissions from the vehicle so that they are not output into the air. If the system is not working right then You will notice that the car has a smell to it, like gas in the cabin. This is not healthy to breathe long term and is harmful to the environment. If the car has to be rated or reviewed for anything it will fail the emissions test as well. For this reason, You should fix the purge valve sooner rather than later.