What is the high fuel consumption of Nissan converse 1.6 manual operation?

Problem description: My Nissan Converse 1.6 has been operated manually for 4 or 5 months, and it is found that the fuel consumption is much higher than when it is 20,000 kilometers. I used to drive a full tank of oil back and forth to the pavilion without refueling. Hello: There are many factors that lead to high fuel consumption. Because I have never seen a current car, I can only help you analyze it. The main reasons are carbon deposit and faults of electronic control system, such as carbon deposit in throttle body, carbon deposit in idle valve, carbon deposit in fuel injector, inaccurate signals of oxygen sensor, air flowmeter and water temperature sensor, which will affect the fuel consumption of vehicles. If the fuel consumption is too high, a comprehensive inspection is needed. I suggest you focus on checking whether the signals of each sensor are normal, whether the carbon deposition of each component is serious, and whether there is any problem with the added engine oil. In addition, during the normal use of the vehicle, the fuel consumption will also change accordingly due to the changes in driving road conditions and vehicle environment.