What does it mean when the engine light on the car dashboard comes on?
4 Answers
There are many reasons why the engine fault light stays on, the common ones are as follows: 1. The oxygen sensor plug is damaged or loose, causing the air-fuel mixture to be too lean or too rich. 2. Poor quality gasoline that does not meet standards, resulting in insufficient combustion of the air-fuel mixture during engine operation. 3. Poor engine maintenance, spark plugs, ignition coils, fuel pumps, or clogged fuel lines causing poor combustion of the engine air-fuel mixture. 4. The engine requires air for combustion. A dirty car air filter that is not cleaned regularly affects the car's air intake. Long-term clogging can seriously cause the engine fault light to come on.
That day when I was driving, the engine light on the dashboard suddenly turned yellow, which made me panic. I immediately pulled over to check. A similar situation happened last time when I refueled at an unknown gas station—the poor-quality fuel caused emission issues, and the oxygen sensor threw an error. I went to a repair shop to read the fault code, spent 200 yuan to replace the sensor, and it was fixed. Common reasons also include a loose fuel cap causing leaks, a clogged air filter, or worn-out spark plugs with excessive carbon buildup. My advice is not to keep driving when this happens; instead, quickly find a reputable shop for inspection. Delaying repairs might damage the catalytic converter, which is much more expensive to fix. Develop good habits like using quality fuel and performing regular maintenance, such as changing the oil and checking filters every 5,000 kilometers, to minimize such minor issues.
Having driven for over a decade, I've encountered the engine light on the dashboard several times, and each instance required immediate attention. The causes were typically oxygen sensor or mass airflow sensor malfunctions—resulting in excessive emissions—or issues with the ignition system, such as incomplete combustion due to carbon buildup from aged spark plugs. Sometimes, the light would come on the very next day after refueling with substandard gasoline—fuel quality really makes a big difference. The most reliable approach is to head straight to a repair shop to read the fault codes with a diagnostic tool—don't try to guess the problem yourself. I know a friend who ignored it and drove for a month, not only seeing a sharp increase in fuel consumption but also damaging the catalytic converter, costing over 3,000 yuan to fix. I recommend keeping an OBD scanner in your car—it's just a hundred-yuan investment—plug it in for a preliminary diagnosis. In short, the light is a warning; taking it seriously never hurts.
When the engine light comes on, I get nervous because it indicates an emission or system issue that could affect safe driving, such as breaking down on the road or even exceeding pollution limits. Common causes include sensor failures—like a faulty oxygen sensor or temperature sensor, leading to abnormal combustion—or a clogged air filter restricting airflow. I remember last year when my car's light came on, it was due to a malfunctioning mass airflow sensor. Delaying repairs for a few days caused the car to jerk and lose power, costing me 500 bucks to fix in the end. It's best to visit a professional repair shop promptly—they can accurately diagnose the root cause. Don’t neglect routine maintenance: regular oil changes, carbon buildup cleaning, and using quality fuel help prevent such headaches. Checking the air filter every 10,000 km, for example, can reduce unexpected repair costs.
