Yeah it isnt a cat on a diesel its a charcoal cannister,makes no difference for the test,plus it will make the car more responsive,better at spooling the turbo,keep turbo temps down so should help with life span + looks a lot better.my opinion mate DO IT!!!!
get one mate best mod, ecept remap ive done on my car!!! they sound awesome and make the car rev alot better. and mine will rev to 5k in 6th gear!! not very often mind!! theres some pics about somewhere ill find them and get back to ya!