Originally Posted by JDM_STYLE

Because it's all in the tune as said many times already and
a flash just uses the OEM settings as a base so it already has
has the info were as a pnp ECU needs more attention as your
basically starting from scratch.

Fuel has nothing to do with the actually ECU itself just the time spent
on the tune and the way you drive it.

If you don't like it get it retuned better or sell it, simple.