Hi all,

Just registerd for my work mate, he's not computer literate so Ive got to do it . He ownes a e320 cdi on a 2000 plate, recently he has had problems with it and been resolved but he still has two problems that a puzzling. The first one is, there is air blowing back through the Inlet which is causing the car to juder while driving at slow speeds but when the car reaches 60 to 70 the car runs really well and smoothley, Any ideas??

The second one is black smoke coming from the exhaust, he has been advised that the CAT may have gone but on his car there are 3, one connected to the turbo and 2 in the middle of the car. Is there a way to check which one is failing as its expensive to change all 3 or is it worth changing all 3?? Any help is appreciated