Hello, I hope I can be of assistance.
Why are the injectors being recoded each time? What is the concern with the car?
Let me know and I'll reply as soon as I can.
Starting I seems really lumpy starting I've been told codes on injectors need recoding fuel efficiency is gone terrible . I've had recoding done on several acassion
if the injectors need recoding then usually the glow plug light will flash and a diagnostic check would give fault codes relating to cylinder (?) knock limit attained otherwise the fault is not due to an injector correction value concern.
It's more likely to be due to deposits on the injector tips causing the injectors to stick which gives a poor injection spray pattern. To confirm this an injector leak off check needs carrying out where the amount of fuel returned from each injector is measured, this would show any injector malfunction.
There are other concerns that can cause poor fuel economy without leaving any fault codes stored, the EGR valve leaking causes over fuelling whcih would give poor fuel economy.
Start with these points, let me know if I can assist further and I'll reply as soon as I'm able to.