ECU issue with my E46

[secrets]

Hello guys,
I will cut right to the problem, I bought my car from a friend and originally it had a 330i engine on it, but the engine was replaced with a 320i M52, the car runs fine but it lacks the 320i power its very slow compared to a 320i, the compression is excellent, everything is good, my problem is with the ECU I guess. the problem is that the ECU is programmed for the 330i not the 320i, my question is: is there a way to reprogram the ecu or add a new fuel mapping or whatever the solution is?

Thanks in advance.

[hakentt]

you need to flash it with 320i software then, have to have proper flashing tools. Or go to professional