Fuel consumption 105km/20L

No , i have replaced everything that causes extra fuel consumption My mechanistic says that the coolant temp must be changed because the engine check light is on. Does that solves the problem ?

Yes, if the coolant does not reach the centerline of the gauge, a.k.a. 'operating temperature', the fuel mileage will suffer, and your catalytic converter and O2 sensors will suffer as well. If your coolant gauge is reading low, the thermostat is likely stuck open or missing. Is there anything else I should know about that is happening with the vehicle? Every piece of information helps as most components will influence the behavior of the vehicle.

Thank you so much for helping me , okay i will change the coolant and i will see what will happen . Thank you

No, do not change the coolant. Diagnostics need to be conducted before anything else is changed. In no way do I recommend changing the coolant.