Cummings isx trouble code help

First off thanks in advance, this forum is full of knowledge from the been their done that crew. I just cringe when I have to take something into the deal or repair shop. I don’t have a lot of confidence in either, not that they are all bad.
I have a 2005 Volvo 670 with a 450 hp Isx that threw a code the other day and was wondering if you could give some ideas for things to look for. It has been huffing a little black smoke and feeling lazy. After it threw the code it started to run awesome and the mileage went from 7.3 to 8.2
It was, MID128 PID411 FMI4
This what I found on the Cummings site 2274 Exhaust Gas Recirculation Valve Delta Pressure Sensor Circuit - Voltage Below Normal, or Shorted to Low Source

Thanks JD

 

Cool thanks for the help, would it hurt any thing to leave it like that and enjoy the added mileage???

 

Sorry my bad, I guess that I should not enter any spelling bee
contests....