Astra J estate engine problems

[Vithu]

Hi, i got a 2014 1.6 astra j estate diesel. My car is currently showing the below error code and has a rough idle. Previously, my car showed the same error on the other 3 cylinders as well. However, the rough idle only happens sometimes and when i clear the error codes, it doesnt reappear for some time. The car also doesnt have this problem for a few weeks if i put fuel additives such as redex. Autostop also hasnt worked for a few months now. The car currently done 110,000 miles and i bought the car in 2018 when it had done 65,000. I checked the service book at 100,000 miles and realised that the diesel filter hasnt been changed since 35,000 miles so i changed it immediately. Im thinking that the driving the car 65,000 miles without changing the diesel filter may have played a role in this problem. I have just been clearing the error code everytime it appears and driving the car as normal but im a bit worried that ignoring the problem is gonna end up in me spending a lot more money to fix it. I use this car for work and drive around 24,000 miles a year. I do a lot of city driving and my job involves a lot of stopping and starting.

P0263 - GM
Type Powertrain - Fuel and Air Metering - ISO/SAE Controlled
Description
Cylinder 1 Balance System Conditions


Cause
Engine runtime over 90 seconds at idle speed, engine coolant at normal temperature, constant fault in CYL 1 and the PCM detected the fuel reduction for CYL 1 exceeded the limit for 2 seconds

 

[Burnerman]

I think it could be a good idea to visit a diesel specialist here, and have the injector performance investigated. The injectors are usually coded to the engine and therefore need a Bosch fuel injection specialist to sort.
John