'03 F150 4.2l V6 w/code P1518

Truck was running fine all day then as I pulled into the driveway the service engine light came on. Did a scan and code says , intake manifold runner stuck open bank 1. I was told they are at the back of the manifold but I can't even get a mirror in that tiny space, let alone my hand. What is involved in reaching these two valves and how do I know which is bank 1? How expensive if I have a dealer check it out?

Hi I just posted the same for our 2003 F150. There is one module in the middle of the lower plenum. Impossible to get to without removing it. I am doing this this weekend. I purchased a F/o LED camera that plugs into my smart phone. We reached around and can see the module. We also are getting the P1518 code. You can see my post. I have no idea how the module reads position if both rods have fallen off?