Smoky Td4 - Help

Hi all.

My td4 has a smoking problem !

Blows a nice black smoke under boost only

Passed mot emissions, runs fine, starts fine, no misfire and no lack of power just black smoke.

Has had,

Replacement recon turbo
New PVC valve
Replaced two common intercooler hoses
Erg bypass fitted
It has also been remapped ?
Any ideas before I take it I'm for some diagnostics at a specialist ?

Thanks

Split turbo hose?

Black smoke sounds like it's running too rich?

Injectors or turbo hose split. Has it been chipped ? if it has this could also be the problem.