Vpod issue losing power

Hi I have 2006 freightliner Detroit 60 series 14l with egr losing power and white smoke when engine reaches normal temperature the shop has already replaced 3 pods 2 turbos ,egr,ecm,engine harness,vpod harness the problem has still not been found after all these parts I still get load of white smoke when engine reaches normal temperature. The shop had tried a used vpod which seems to work but when they replaced it with new it cut out and start misfiring white smoke no power again. I am totally stressed out can someone help please thank you in advance

 

Yes they checked the air pressure to vpod and not the egr cooler yet

 

Could egr cooler cause this but how would an old vpod work fine and not new one so far and they swapped and swapped like 4 vpod only 1 old seen to work so far and also changed the vpod harness

 

Detroit?? Currently it's in a shop with 3 certified mechanics

 

K thx