SPN 102 FMI 18 CM2350

[Aardvark]

I have been getting the above code despite changing the IMAP sensor with genuine Cummins sensor, doing a complete EGR tune up and have checked for leaks on both sides of the air charge lines. I am at wits end as truck will run on flat and down hill normally but just the slightest incline puts me down to road hazard speed. What else can be contributing to this code that I am missing? I have been scouring the forum for 2 months trying to find info on this. Thanks in advance