stock 6.0 truck blowing black smoke NEED HELP???

[BGLUKE]

i have a bone stock truck with a six speed manual that just come back from the shop. it had a check engine light on and they said it was injector failure. the truck ran good before i took it in and after i got it back the truck has no power even with the codes erased. i put cetane boost and ijector cleaner in it like they said to do and it didnt help any, that was three days ago. it also blows bluish white smoke during low rpms before the turbo spools up when shifting then changes to black smoke. i havent talked to the mechanic yet since it went in for work he wasnt there this past weekend.

[OT]

BG..your Q. is odd..if repairs done & worse after, did you ask who every worked on your 6L why? Black smoke is probably unburned fuel. Blueish smoke..oil burning etc. White could be water vapor?