You need to get the emissions FSM. It clearly shows where the vac hoses are routed for every emissions component. It also tells how to adjust idle mix for best emissions performance.
There are links on this forum to download a PDF of the emission FSM.
Thanks Jim. I have it. It’s even printed. I’ll look through it again as I only had the main schematic at the truck when I worked on it. Which is clear as mud. Had to come inside the house and reference the computer each other time. Need to get a binder or put it on an iPad.
I’ll report back after more head scratching, staring and wrench turning.