Where is the damage when the air-fuel mixture is too lean?
2 Answers
It is caused by the damage of the intake sensor and the front and rear oxygen sensors on the muffler, resulting in a lean air-fuel mixture. Excessive carbon deposits in the vehicle's engine can lead to improper feedback from some components, causing the vehicle's computer to determine that the air-fuel mixture is too lean. The following is an introduction to engine carbon deposits and oxygen sensor damage: Engine Carbon Deposits: Carbon deposits include cylinder carbon deposits, throttle carbon deposits, spark plug carbon deposits, and intake carbon deposits. These areas are closely related to the engine's power output. When there is excessive carbon buildup inside the engine, the vehicle's ignition energy decreases, intake efficiency drops, ultimately leading to reduced engine power and symptoms such as shaking and poor acceleration. Oxygen Sensor Damage: As an internal control unit of the vehicle, the oxygen sensor primarily monitors the fuel-air ratio of the engine. Once damaged, it can cause an imbalance in the engine's fuel-air ratio, inevitably leading to abnormally high fuel consumption. During driving, the exhaust pipe will emit darker-colored exhaust gases. At this point, the oxygen sensor should be replaced as soon as possible.
Last time I encountered a similar situation was when driving on a mountain road, feeling a noticeable lack of power, and the engine malfunction light suddenly came on. After taking it to the repair shop for inspection, it turned out to be a cracked vacuum hose causing an intake leak, which led the mass airflow sensor to misjudge and reduce the fuel injection amount. For such issues, it's usually best to start by checking the intake system. Inspect all rubber hoses for aging or cracking, with particular attention to the pipe connections between the throttle body and the intake manifold, as leaks there are most typical. Also, check if the mass airflow sensor has carbon buildup causing false readings, and ensure the intake air temperature sensor isn't faulty, as this can also lead to incorrect fuel injection calculations. If you encounter a lean fuel mixture, don't rush to replace the oxygen sensor—many cases are simply due to issues with inexpensive hoses costing just a few dollars.
