What does it mean when the car's engine light comes on?

[MacGenesis]

Reasons for the car's engine light coming on: 1. Poor quality gasoline not only leads to incomplete combustion of the air-fuel mixture in the cylinder, producing excessive carbon deposits, but also poses risks of clogging the fuel system and corroding components, directly affecting the normal concentration of the air-fuel mixture, resulting in the engine light illuminating accompanied by shaking; 2. Carbon buildup on spark plugs causes poor engine performance, manifesting as difficulty starting, unstable idle, poor acceleration, backfiring during rapid acceleration, and excessive exhaust emissions; 3. Engine misfire leads to increased fuel consumption, black smoke emission, lack of power during acceleration, severe shaking, increased engine noise, and a higher likelihood of stalling, causing the engine light to come on.

[LaJuliet]

Last time the engine light on my car came on, and it turned out to be a faulty oxygen sensor after inspection. This thing monitors exhaust emissions, and the light comes on when it fails. Actually, there can be many reasons for the engine malfunction light to illuminate, such as issues with the mass airflow sensor, aging spark plugs failing to ignite, or the fuel pump not supplying enough fuel. More serious causes could include cylinder pressure loss or a faulty knock sensor. I suggest you don’t panic right away—try restarting the car first, as sometimes it’s just a temporary fault code. If the light stays on, quickly use an OBD scanner to read the trouble code and pinpoint the exact issue. Definitely don’t keep driving if the light persists—if it’s a major problem, you could damage the engine. It’s best to get it checked by a reliable repair shop as soon as possible. Safety first.

[DamianAnn]

I've encountered the engine warning light suddenly coming on several times, and each time it revealed a new issue. The most common problem is sensor malfunctions - the pre-catalytic converter oxygen sensor is particularly prone to failure, and replacing it usually costs just a few hundred dollars. Sometimes it's fuel-related, like when poor-quality gasoline triggers the warning. Essentially, this light functions like the engine's health report, indicating it's time for a check-up. My routine is to first verify the fuel cap is properly tightened, then observe if there's noticeable vibration or power loss. If acceleration feels normal, it might not be serious. But if accompanied by stalling or weak acceleration, it's safest to immediately pull over and call for a tow truck.

[DeChristopher]

There are three main reasons for the engine light to come on: sensor failure (such as the camshaft position sensor), fuel supply system issues (like a clogged fuel pump or injector), or ignition system failure. First, check if the fuel tank cap is tightly closed, as this is the simplest scenario. Then, pay attention to the engine sound; if there is noticeable shaking or unusual noise, do not continue driving. The most practical solution is to purchase an inexpensive OBD scanner (costing around a few tens of dollars) and connect it to your phone to read the specific trouble codes. This allows you to troubleshoot minor issues yourself, saving both time and hassle.