2007 Freelander 2.2 nightmare

Hi all hoping some one can maybe help I have bought a Freelander 2.2 and I cannot get it running rite at all it’s had 4 injectors new egr and airflow Meter it’s starts off the button but runs lumpy as hell and chucks white reak out of back defo over fuelling for some reason once up to temp it runs bang on boost we’ll no splutters or out fuel pressure is good Etc via diagnostics bit stumped with this one I am a mechanic to trade and it is my job just wondered any of you guys come across it before I hazard a guess and waste money cheers