I have a 2001 24v with 236k on it just put a new timbo Apps and apps isolator in the truck 5 months ago and at the same time i put a new map sensor from cummins in because i could hardly accelerate and had p0121 code along with p0237 well replacing the apps and map sensor fixed it.

Now i am having a very lower power and surging problem when i am trying to accelerate it will just creep forward no matter how far you press the accelerator then all of the sudden it will try to accelerate then rpm drops and engine just about dies then returns back to idle. codes did trip and are p0122, p0236, P1693 I have tested the apps and its within operating range i also tried unhooking my edge comp box and finally i also tried putting my old apps on the truck and resetting it that didn't do anything either so i put my timbo back in and reset the apps again.

I will add that for a wile now i have thought my vp44 was going out because driving down the freeway at 75mph i can watch my fuel pressure and it is at 14psi but then will suddenly drop to 8psi and then spike back up to 16psi and then settle back to 14psi and would continually do this but driving around town no drops or spikes in fuel pressure.

Any help would be appreciated

I don't want to go spend a ton of money on a new vp for it to not fix my problem
and still be in the same boat.

so you know what the truck is
2001 Dodge Ram 2500 4x4 auto
I have a 5" MBRP exhaust Straight pipe with 4" down pipe
Edge Comp box
timbo Apps
BD X hook on turbo
Fass 95gph Direct replacement
Stock injectors
stock VP
New map sensor from cummins