Grand C-Max 1.6TDCI - Injector issue P1262

Hi all,

My dad has a 2011 Ford Focus C-Max Grand 1.6tdci that has developed a bit of a fault with an injector or two, and im wondering if its just coincidence/age related or a symptom of a greater problem.

77,000 mileage and he only does 4,000 miles a year since covid.

Back in April/May this year a warning light came on and the Cmax went into limp mode, ODB scanner said P1264 Cylinder #4 high to low side short

A few days later it went into the garage and had a new injector fitted, its been running ok since if a little rough at times.

Last week it again went into limp mode again, i checked using both the odb reader then forscan and both come back with P1262 Cylinder #2 high to low side short.

There are a few other warning codes but whether they are an issue or just forscan not being able to read all the codes.

DTCs in PCM: U0418:00-28
DTCs in ABS: U0401:00-68
DTCs in RCM: U0415:00-28
DTCs in BCMii: B10EF:12-6C
DTCs in IPC: U0164:00-6C

After resetting the codes the car will idle fine on the drive, the P1262 does not reappear and the car ticks over just fine, maybe a bit lumpy.

As soon as you drive 200 yards it goes into limp mode and the P1262 code reappears.

Leaving the car over night and the P1262 code disappears.

Now im wondering if 

a) all the injectors need replacing / reconditioning

b) a problem with the fuel system/pump/filter

c) an electrical or pcm issue

d) low mileage is causing dpf or some other issue 

Whilst it is booked in this week it would be good to get to the actual cause of the problem and not just replace parts in the hope it fixes everything.

Thank you for any help

Its booked in the garage for la

Dad 007a.txt