Finally have some work done. In order to weld that bung on the pipe I did a little homework and watched this first
https://youtu.be/1kPJ03FGYMY I learned a bit with that . Since the bung I have wasn't curved to match the pipe like he recommended, I contoured it myself on the bench grinder. Then I drilled the proper sized hole with a step bit and clamped it on the pipe with a big hose clamp. After finally getting a leak free weld, (I like to cap of the pipe with my hand and fill it with water to look for seepage) I thought I was good to go but noooooo..... Too bad the pipe mounting flange for the manifold was on the wrong side of my work and there was no way it was sliding over that bung to go back up the pipe where it belongs. So... I split the flange open with a Sawzall, spread a bit and slipped it past my work then welded it back together again. That was a rookie movie for sure. One thing I did that was smart however, was to buy a threaded plug for that bung to use a heatsink during welding and for protecting the threads during mockup.
Anyhow once I mocked it up on the truck the location was just where I wanted it so I quit for today. I'm going to pull the pipe off the truck once more and use my Dremmel to grind off a tad of the pipe inside the bung as I was just a wee bit off center when I welded. The sensor just drags on the overage slightly causing it to not want to thread right in by hand. Then I'll paint the welds with cold galvanizing compound and I'll be back here.