No catalyst (Lambda probe, nox probe) consumption

Hello MY SAXO VTS GROUP

1.4, 160 thousand kmts, the previous owner took the catalyst, the issue is that it is consuming 9 km / liter.
The question is:

what should I do so that the consumption of gasoline is the minimum possible, as I understand this would happen with a poor mixture in gasoline, but not having the catalyst the Lambda probe and the NOx probe can confuse the computer to send a naphtha rich mixture that would cause greater consumption.

What can I do to solve the consumption problem?

As I read, it seems that there are simulators or emulators of Lambda probe or that the computer can be configured to make consumption minimum, is this true? any track?

Thank you very much for any comments about it
greetings
Mauro

The first thing is that you look for one in scrapping and put it, do not listen to jilipolle that it will be better without it .. the calculation is the one that is and there is no more, unless you want to change injectors, switchboard and everything to get out more expensive than 16v, I have a caliber that came like this, and it would not use anything without catalyst, also the pole empty it because it was broken because it was broken because it was broken because Ponsate and leave, pay me attention if you want, Citroen engineers are not idiots, think about it ..