help please

[Bowtie boy]

my truck keeps throwing this code. po449 evap control system vent valve/sol circuit malfunction. Anybody ever had an issue with this?

[oleshifty]

try gas cap first...normally fixes emission code. if not, check vac lines and purge solenoid

[Bowtie boy]

yea I checked the cap. It seems to be running fine so I didnt think it would be a vac leak. anything else

[farmtruc]

i see this all the time, if nothing is wrong, then just have it turned off in the tune.
i know of customers that have had the dealer change every part out and the pcm will still set this code, weird.

[GasGuzzler]

Let's try to know the system and what is does before we answer.

This is a common issue on 07 GMT900 trucks and is usually the vent valve open electrically. Use a scanner to turn the vent on and a test light on the two circuits (power and ground ) to verify the valve is dead.

It's easy to replace.

[Bowtie boy]

the valve is the the thing on the back of the tank?

[GasGuzzler]

Ummm....that's relative to so many manufacturing differences like year and bed length and cab type but you're close.