Tech had customer run washer, kitchen sink and dishwasher, to allow leak to show itself at the top of the wye. Tech discussed pricing and procedure with customers. Once tech was authorized have duct was moved out if the workspace, leaking fitting was removed, and a new pvc fitting was installed. Line was then tested ensuring proper drainage and no leaks were present. Once all fixture were tested and fitting was determined to be leak free, vent elbow was reinstalled.