I program car with Volta generated file, and after this car starts smoking.
Generally this car is in bad condition. Injectors are really noisy.
Now I don't know whether to blame ecu_mod or look for the cause further.
Can anyone verify that it is as well?

You must write ori file back, reset DPF on this BMW, and check injectors. Your problem will be both: software and hardware side. Volta is not doing a good enough job. Far from that.