Hey Guys. i have a 2001 focus 1.8 tddi. It was going great and really pulled well through the gear. i decided to give her a service saturday and since then it seems dead in 2nd 3rd 4th and 5th untill it gradually gets upto speed. i changed the air filter, diesel filter, oil filter and oil. all the correct parts so have i upset something whilst fiddling?? anyone have this before?? Help please.