Hi all please help last year i bought my audi a4 on a 55 plate, after a while of owning the car the turbo blew sending shards of metal fragments through the intercooler and up into the egt valve/throttle body. I have had a lot of work done on the car including, a full service, cambelt, waterpump, turbo, intercooler, egr valve, maf sensor, map sensor, boost control valve and n75 valve. The car was then perfect, in the last few months the car hesitates between 1000 - 2000 rpm, and chucks out a bit of black smoke, this is with the maf unplugged, plug the maf in and it runs terrible, coughs and splutters and wont boost right and guffs out black smoke. Please help??