What causes the engine malfunction light to suddenly come on and the car to shake when accelerating?

[DelKatherine]

Reasons for the engine malfunction light suddenly coming on and the car shaking when accelerating: 1. Damaged spark plugs, where the wear of the spark plug electrode gap leads to insufficient spark ignition, causing incomplete combustion of the air-fuel mixture and resulting in shaking during acceleration; 2. Poor quality gasoline, leading to inadequate atomization by the fuel injectors and incomplete combustion of the air-fuel mixture in the cylinder, which can also cause idle shaking; 3. Faulty oxygen sensor, where damage to the oxygen sensor or its connector, or loosening, can cause the air-fuel mixture to be too lean or too rich, triggering the malfunction light; 4. Faulty mass air flow sensor, which measures the amount of air intake and converts it into an electrical signal sent to the Engine Control Unit (ECU), indirectly allowing the ECU to determine the amount of fuel to inject. If the mass air flow sensor or its circuit malfunctions, the ECU will not receive the correct air intake signal, leading to improper fuel control and causing the air-fuel mixture to be too lean or too rich, preventing the engine from operating normally.