hi stuggling with this one and its my brothers vehicle exessive black smoke and down on power he was driving ok then he saw smoke from behind and a drop in power. there is no stored data the egr looks ok and i have removed to check valve timing is ok, no restriction in the manifold we have dropped the exhaust and still the same the turbo will boost although a little late .by removing the inter cooler pipe from manifold it revs a little more freely but still smokes i think it is a fueling issue any ideas ??