Replaced the fuel filter and all is back on target. Intake air mass is up from 210 g/s to 248 g/s, low fuel pressure after 6k rpm is up from sub 4.0 bar to greater than 5.0 bar. High rail pressure is up from sub 120 bar to greater than 130 bar. Looks to have maybe gained 15 hp by turning down the boost from 23.5 psi(over specified) at redline to 18 psi(equal to specified) at redline, and then by replacing the 6.6 bar filter.