Background: 2010 Dodge Ram 2500 SLT RWD 6.7 Cummins, 220,000 miles, purchased from nephew who bought new, Smarty tuner with EGR deleted, was running towing setting on Smarty.
On occasion, I would notice a hiccup while driving, but, nothing consistent. Many times, I would change the fuel filter and any hiccuping would seemingly go away.

Now the truck noses down around 2000 rpm. It is drive-able, if I stay in it, but with significantly less power and the engine sounds "hollowey". I have to let off the pedal because of the power loss. When I let off the pedal, the power will return in a few seconds after rpms have dropped way down and the "hollow" sound goes away.
First item up on the agenda was the fuel filter. I replaced it with no effect. I have replaced the lift pump with a Fleece unit and replaced the filler neck. I started there because I thought my rusting filler neck might have damaged the lift pump. Starting has gotten easier, but problem remains. I then replaced the CP3 fuel injection metering unit with a Bosch replacement, no effect. I then replaced the rail over-pressure device with a plug, no effect. I then replaced the rail pressure switch with a Bosch unit, no effect. The next item up on the agenda appears to be the CP3 pump. Does anyone have any suggestions for me? Before I started working on it, I returned it to the factory tune and checked for DTCs. There have been no DTCs this whole time.

 

Sure sounds like tired injectors. I would send them out for rebuilding, if it were me. I used F1 for mine years ago and it cured the 'hiccups' in my '03.
Back to morning brew . . .

 

It finally threw a P2262 code. I have to research this now.

 

Sounds like turbo time.

https://www.turbodieselregister.com/...2-code.244112/

https://www.cumminsforum.com/threads.../#post-4074491

 

Thanks. Indeed it was. I have a 10 month old at home that takes up all my time. I finally got the stocker swapped out with an Aurora 4000 VGT and the nosing down has ended. I suspect the actuation process was gummed up. With the stock tune it pulls hard. I am not sure I want turn it back up. I might roast my 68RFE.