V50 Diagnostics. ECU relearn? Injector fault?

[clfurness]

Hi all,

Diagnostics.

I have an issue, possibly with an injector, possibly not.
Anyway, I need to diagnose the fault properly before work starts.
The dealer advised me that only they can read the codes properly, and standard diagnostic tests won't give me sufficient information.
Clueless right now. Please help!

Will post more info about the specific issue below, if anyone else has had a similar experience.
Cars a V50 D2 2011

Full story:
Basically, a year ago it seems like the ecu got reset during a service due to the battery being disconnected too long, and it lost all this data that helps balance the cylinders through the micro injections of disel throughout the cycle.
Because it lost the data the engine run like a bag of spanners.
'Fixed' that by driving +20km accelerating from 1500rpm up to 2500rpm then letting it fall back down naturally to allow the ecu to rebalance the engine. This worked, but there must be a root cause...
That was a year ago. Happened again a week ago, which makes me think theres a physical fault leading to the imbalance like a injector seal or something.

Thanks for reading.