Disconnect the EBP sensor and try it.

Do you have a way to look at Baro, MAP and EBP all together at idle? They should all be very close.

MAF/IAT1 sensor connected up?

IAT2 sensor issues can also cause power problems. Is it properly connected?

Are you getting good fuel flow to the upper fuel filter? I assume you do not have a fuel pressure gauge? It is very helpful in troubleshooting and worth getting.

Is the oil level OK - extreme level and/or fuel dilutiuon can be a problem that could create low power.

I would guess that you have made sure that there are no extreme intake or exhaust leaks?

Codes would be nice as Steve suggetsed. Is the VGT solenoid properly connected?