has it had a fuel pump recently? if you have a scanner you can command the vent sol on or off and see if its actually working. you may have to go to the dealer for it, or it may be part of the fuel pump assy. when it comes to engine management AZ would be the last place I went, unless of course you dont mind doing it again in a month. Unfortunately it will need to be checked out, evap sucks to debug without the correct equipment.