I had two new codes pop up after a stall tonite , maf and egr, after that I reached back in around the ficm pulled on some wires , and got the injectors to click. I then tried to push them around again to see if I could make it stall or at least run rough but no luck

Noticed today, under acceleration, ficm dipped to 46.0, not sure if that’s a big enough drop to affect anything though?

The pid readings would help also if you can see them. Do you have any smoke while cranking or at idle? If you can pull pids KOEO and cranking pids that might help you find either a general idea to look would be ficmv ficm sync. Also check the crank and cam shaft sensor sync if for any reason the ficm drops below 45-46 45 being lowest not recommended to keep on cuz it might cause injector failure over time not once or twice. If for any reason. You lose sync on cam and crank sensor it can cause it to die as I have been told not sure tho on that if i am wrong please let me know so I will know for the future most of my suggestions are based of of years of research as well as working on them but I still have so much to learn. These sensors will not sync until cranking. I would watch them while at idle just to be on the safe side sorry for the book just trying to give reasoning behind these. Is it a certain time of year? Or season weather does any of this change it (makes worse or better) if you have not figured problem out might be a loose or damaged icp sensor wire

Everything looks good, Icp rpm, everything sync’d while running
Today I replaced a body to frame ground strap and pulled the cover in the ficm to test it(7 pin)
It would barely get to 16 volts, key on engine on or off, and this is while the scanguage shows 48.5 volts.
I did notice under hard acceleration ficm dropped to 46, and ran a little rough, also being warm might make the problem more pronounced- it’s hard to tell

Are you sure you have the correct lug? That's a big discrepancy from your measurement to the SCANGAUGE. This is from the procedures I have:

"4. if you have a "7 lug FICM"...you want to put one lead from your
multimeter onto the upper left "lug"...and the other multimeter probe
to ground (bare spot on the cylinder head, alternator bracket, negative
battery terminal, etc). If you have a "4 lug FICM"...you will want to
check the lug on the right (closest to the drivers side fender). Be
careful NOT to lean the probe on the FICM lug...overonto the
aluminum case...you might let the smoke out, LOL.."

Seems to me you might be chasing nothing with the FICM. I think 46 VDC is OK. If you want greater, maybe a 58 V FICM would be good. May be starting to fail, it's whether you want to change it for piece of mind when it can be good for years to come.

It’s the upper right pin as it sits in the truck ( I did double check and I did get the right one )
is there any other reason why I wouldn’t get 48v and the ficm still be good? I don’t want to replace anything that I don’t need,

Haven't done the test myself, but as I read the instructions, should be the left, not right as it sits in the truck for the 7 pin FICM.

I bet it depends on which way you are facing the truck. If you are standing at the grill you are correct, it’s the top left, but if you’re at the fender it’s the top of the right row of four

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I've wandered about this.
Is it really possible for the ficm to read good through torque/forscan/etc while its actually putting out lower?

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Update to the thread, I ended up selling the truck before figuring out what the problem was. I know the new owner, so I can find out what the issue was and post it up