Black Smoke & Codes P0101/P0401

[glivingstone]

Well guys all was going good with the beast until today.
While towing 3 horses down the road I lost power and noticed tons of black smoke coming from the exhaust, luckily I was able to limp home at about 60KPH.
No MIL light so I checked for codes using the CarCode and found 2 X pending codes:
P0101 Mass or Voume Air Flow A Circuit Range/Performance.
P0401 Exhaust Gas Recirculation Flow Insufficient Detected.
Pulled off the air cleaner and checked all looked fine, checked the turbo fan and seems to be free spinning.
Anyone experienced similar problem or have any suggestions?

[DmaxMaverick]

Probably lost vacuum. Check the pump, lines and valve(s). Vacuum controls the EGR and wastegate.

[glivingstone]

Well guys I think I found the problem, the EGR valve was stuck on.
Pulled the vacuum line off the EGR and it was sucking hard at idle.
Pluged the vacuum line for a temporary fix but she keeps throwing codes:
P0401 Exhaust Gas Recirculation Flow Insufficient
P0400 Exhaust Gas Recirculation Flow
Think it may be the vacuum switch playing up, anyone have any ideas?