What is broken when the mixture is too lean?
2 Answers
It is caused by a damaged intake sensor or a faulty front/rear oxygen sensor located on the muffler, leading to an excessively lean air-fuel mixture. Excessive carbon buildup in the vehicle's engine can cause improper feedback from certain components, prompting the onboard computer to determine that the vehicle's mixture is too lean. Below are explanations of engine carbon buildup and oxygen sensor damage: Engine Carbon Buildup: Carbon deposits include cylinder carbon buildup, throttle carbon buildup, spark plug carbon buildup, and intake carbon buildup, among others. These areas are directly 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, and ultimately, the engine's power is reduced, resulting in shaking and sluggish acceleration. Oxygen Sensor Damage: As an internal control unit in the vehicle, the oxygen sensor primarily monitors the air-fuel ratio of the engine. Once it is damaged, it will cause an imbalance in the engine's air-fuel ratio, inevitably leading to abnormally high fuel consumption. During driving, the exhaust pipe will emit darker-colored exhaust gases. In this case, the oxygen sensor should be replaced as soon as possible.
A lean fuel mixture usually indicates an imbalance in the air-to-fuel ratio in the engine. Common causes include clogged fuel systems or leaks in the intake system. I've encountered this issue a few times while driving, with symptoms like engine shaking or unstable idling. In such cases, I first check if the fuel filter is clogged, as insufficient fuel pump pressure can also lead to inadequate fuel supply. Additionally, if there are tiny cracks in the intake manifold or vacuum hoses, air can sneak in, making the mixture leaner. I recommend simple tests, like starting the engine to listen for hissing sounds indicating leaks or disconnecting the fuel line to check pressure. Ignoring repairs can, over time, damage the catalytic converter or cause engine overheating, leading to more expensive part replacements. Regular maintenance, such as using good-quality fuel and periodic injector cleaning, can prevent this issue. If unsure, it's best to consult a reliable mechanic for diagnosis—safety first. In short, don’t wait until the warning light comes on to address the problem.
