Does anyone know if its possible to reset an ECU such as disconnecting the battery will that reset it back to like a factory default setting? or unplugging the ECU multi plug?

Just trying to cure an ongoing problem which dealers can,t solve so was wondering if i can reset the ECU would that make my car act like when i got it from new?

Sorry for babbling on but any help would be greatly appreciated

Not really no.

You can reset adaption values by creating a fault code on the engine controller 01 and then resetting it.