Had P0446 code dealer replaced Valve 9945 and solenoid FD6L3Z/9F945/A eng lite

first thing to do is check the dtc's again to make sure the same code came back,if so next do a check on that circuit check to make sure ecm is commanding vent solenoid on and off when it should and check for broken / chaffed wires.also check valves to be sure a defective one was not installed. if you need help we can do that for you just give us a call and we'll set it up 610-867-3088