The fuel consumption of Nissan Style A33 has greatly increased for no reason. Please advise how to solve it. ...

Your situation is quite common, but it is technically complicated. Let me give you a brief explanation.

From your description, it seems that you drive more in the city. Driving in the city for a long time, the engine speed is low and the mixture is thick, which is easy to form glue at the fuel nozzle and accumulate carbon in the combustion chamber. Poor atomization of fuel injection and carbon deposition during combustion will lead to disorderly early ignition and reduce combustion quality. At this time, the judgment of the engine computer has gone wrong, and the throttle will be adjusted immediately (the throttle itself is not necessarily wrong) to improve the air-fuel ratio, further increase the fuel supply and form a new balance.

The solution must be to clean the fuel nozzle and remove the carbon deposit in the combustion chamber, but I can't agree with the method of 4S shop. Some of them are cheating people, but they have caused problems.

Simple solution: buy "multi-channel membrane" online and use cleaning products. About two boxes will solve your problem.

I am in Chengdu, waiting for your gas card. ...