05 TD4 juddering when accelerating and occasional lumpy idle

Got the car back yesterday, was a faulty number 2 injector, car purrs like kitten now!

They said it was intermittant and when they first ran the diagnostics the injector was fine. It was only when they ran the test again (when they ran out of ideas) that they found it was faulty.

I find it really strange that changing the autobox fluid improved things considerably for a few months though?

Thanks for all the input and advice.