I have a a Tahoe that i just bought and it thru a code today about the evap system ....PO446 and i have checked all the hose connections and unplugged and plugged electrical connections .....there seems to be only three main parts evap canister, purge valve and vent valve ...only thing is how does one go about checking to see if the valves are working right

chilton say most often its the hoses or canister that fails first

guess i'll have the dealer may be smoke the system for leaks

has anyone else had this problem