I was getting a Code P0456 on my 2007 Highlander and wanted to troubleshoot it. Checking out the service manual, I found reference to the Service Port which should have been connected to the hose assembly (23820-20210.) However, my highlander did not have this port which I found was part number: 77739-06010. Were these not installed on all Highlanders? And is there any reason for me to install one?