P0449 says that the PCM is not seeing the voltage potential it wants to see when the vent valve is off or commanded on. I would suspect it is the Evaporative Emissions (EVAP) Canister Vent Solenoid near or on top of the gas tank is bad. To make sure check the voltage at the pink wire. It should be around 12 volts. If it is low, it may be bad wiring or the PCM, but not likely. if you have 12 volts suspect the solenoid.
The 2006 GMC Canyon has 16 valves.
The 2006 GMC Canyon has an inline 4 engine.
The 2006 GMC Canyon is a gas-powered vehicle.
The 2006 GMC Canyon has a 5-speed manual.
Desolation Canyon was created in 2006.
The 2006 GMC Canyon has double overhead cam (DOHC).
The height of the 2006 GMC Canyon is 5 ft. 5.5 in. (65.5 in.).
The 2006 GMC Canyon runs on regular unleaded.
The 2006 GMC Canyon's turning circle is 39.4 ft..
The 2006 GMC Canyon is 16 ft. 0.4 in. (192.4 in.) long.
Under drivers side of dash.
The ground clearance of the 2006 GMC Canyon is 0 ft. 7.9 in. (7.9 in.).