the car has a new turbo and has just had a new vacuum pump fitted. intercooler and pipes where cleaned and new oil pipes and gaskets where fitted. car smokes abit when normal driving then turns black and is abit now when you put your foot down. been advised it might be a blocked exhaust/cat or from inlet side. how do i find out which one is the problem. could it be to do with the egr valve

ab, September 2012

it could be sticking egr valve,sorry never done one of these but that would be worth a look and also it may be worth getting a couple of tins of fuel conditioner,try and get some of it direct into the filter and the rest into the tank and that may help your black smoke also,good luck

cdc, September 2012