Picasso 1.8 16V gasoline excessive consumption

I have a Picasso Gasolina 1.8 16 valvular and consumption is triggered at 11 liters I have changed spark plugs, gasoline filter, air filter and nothing remains the same. Someone can tell me what to do have told me that you can modify the injection map by putting it on the machine, but I do not know if it is true, I would not mind even if the CV would go down, because I always travel alone in it and I do not need the 117CV that someone helps me or gives me some idea to lower the consumer, I know what to do thank you