What to Do When the Engine Malfunction Light Comes On After Refueling?

[StPeter]

If the engine malfunction light comes on after refueling, it indicates that poor-quality fuel has been added. During the combustion process in the engine, due to the high impurity content and low combustion efficiency of poor-quality fuel, some impurities and unburned fuel accumulate in the combustion chamber, occupying space and causing the engine malfunction light to illuminate. Solution: Promptly drain the poor-quality fuel and clean the fuel tank and fuel lines. After cleaning, replace it with high-quality fuel. Apart from fuel quality issues, the engine malfunction light may also come on due to the following reasons: Sensor Malfunction: The sensors mentioned here include coolant temperature, crankshaft position, air flow, intake air temperature, oxygen sensors, etc. When these sensors are damaged, have poor contact, or experience signal interruption, the car's ECU cannot accurately obtain engine data, leading to the illumination of the engine malfunction light. Poor Combustion of Air-Fuel Mixture: Poor combustion of the air-fuel mixture can cause engine carbon buildup or knocking. When detected by the oxygen sensor and reported to the ECU, the malfunction light will illuminate as a warning. Issues such as spark plug failure, ignition coil failure, fuel pump failure, or clogged fuel lines can all lead to poor combustion of the air-fuel mixture. Turbocharger Issues: Intake boost pipes and turbochargers can also cause the engine malfunction light to come on. The most common issue is turbocharger damage, accompanied by symptoms such as oil leaks, excessive oil consumption, reduced power, metallic noises, or blue/black smoke from the exhaust. Intake Issues: If there are problems with the car's air intake, it may lead to clogged engine pipes, and in severe cases, the engine malfunction light will illuminate. A dirty air filter that is not cleaned regularly can cause intake problems. Exhaust Issues: Exhaust system malfunctions can also trigger the engine malfunction light. Common causes include rear oxygen sensor failure, catalytic converter issues, exhaust camshaft and bearing failure, with the catalytic converter being the most frequent culprit. The use of leaded gasoline, lead or silicon-based lubricant additives, physical damage to the catalytic converter, or fuel system malfunctions can all easily lead to catalytic converter failure. Anti-Theft System Malfunction: If the car's electronic anti-theft system malfunctions or the anti-theft controller does not match the engine electronic controller, the anti-theft system can prevent the engine from operating normally, and the engine malfunction light will illuminate.