Volvo d13 2013 truck will not go over 45mph? Egr stuck open?

EGR has nothing to do with fuel pressure falling to Zero

 

I’ve had this problem happen I had a restriction befor the fuel filter it had a water separator on the fuel housing in the engine and found the elbow stuck with cigar leaves that truck would only go to 35 and then choke up.

 

Have you done any repairs, right before this symptoms showed up? or PM/oil fuel filters replacement?
I got a similar problem years ago on my last truck with D13, after a PM oil change at TA in Georgia.
When the technicians removed the fuel filter, it came out with this threaded section/ pipe , which was supposed to stay on filter housing . They told me they heard something falling in oil drain , but couldn't find what was. It was the piece i encircled in red bellow,( just a random volvo pdf, but it's same on D13) , this hexagonal part, it's like a bullet ,inside the fuel flow , regulates the fuel pressure, with its weight i believe, gravitational . So, they installed the filter without it, i got same symptoms as you describe, i bob tailed to Atlanta slowly 45 mph, low fuel pressure warning, and paid 1000$ for a new housing. I knew i need that piece only, but Volvo don't sell it, should be available for 2$, spare in any lube shops authorized to do oil changes for Volvos, because it happened 6-7 times after to see the fuel filter coming out with that threaded mounting pipe, but i pay attention and tell them.
Just some thoughts from my bad experiences.



I found a photo;

 

If you have normal fuel pressure until the truck reaches 45 mph, then drops, could be speed derated not fuel system problem; The ECM cutting off the power /fuel for some reason, maybe doesn't meet some emission settings. I have 13 speeds manual, when i got derated for emission faults,i unplugged the speed sensor from the back of transmission to keep moving, monitoring the speed on digiHUD app on my phone, or any speed gps navigation toys.
You can try this, but if you have I-shift don't know if can unplug speed sensor. If the truck runs normal over 45 mph with the sensor unplugged, at least you'll know is not the fuel system.

 

If there was air there would have been out by now. How is the truck starting when u let it sit over night does it crank for longer than 45 sec. if yes hit priming pump does it help. If yes need to do compression and balance test with PTt to check injector response.