Aye, just looked at tuneside visit.
To me if it's ruled out to be the intercooler, I would start looking at the fuel pump (or is yours a PD?) and it's timing plot. If it's out it will fire too much fuel in, and also at the wrong point on the engine stroke.
If it is down on power, then it would be more of a case of looking at injectors as they are unit pumps and can fail individually.