The orange, engine-shaped icon that sometimes appears in your car’s instrument cluster isn’t just a nuisance - it’s a sign that something is wrong under the hood. Ignoring it could leave you stranded at the worst moment, cost you thousands of rupees, or both. The check engine light warns of issues ranging from a gas cap that’s not properly tightened to a more serious failure like a bad catalytic converter or a problem with one of the car’s oxygen sensors.
Here are the 10 most common problems that can trigger a check engine light:
1. OXYGEN SENSOR FAILURE:
The oxygen sensor (sometimes called an O2 sensor) measures the amount of unburnt oxygen in a car’s exhaust system. It sends data to the vehicle’s computer, which uses it to regulate the mixture of air and fuel that enters the cylinders. A car will keep running even if an O2 sensor needs to be replaced, but it will burn more fuel than usual. In the long run, a bad O2 sensor can damage components like the spark plugs and the catalytic converter. It may also cause a car to fail an emissions test.
2. LOOSE FUEL CAP:
A loose gas cap is one of the most common reasons why the check engine light turns on. The cap is a crucial part of a car’s fuel-delivery system. It notably prevents gasoline fumes from leaving the fuel tank, and it helps keep the whole system under the correct pressure.
3. CATALYTIC CONVERTER FAILURE:
A catalytic converter is integrated into a vehicle’s exhaust system. It turns the carbon monoxide generated during the combustion process into carbon dioxide. It’s a fairly simple part, and its failure can often be prevented.
4. SPARK PLUG/IGNITION COIL ISSUES:
Put simply, an ignition coil generates the electricity the spark plugs need to ignite the fuel and air mixture in the cylinders. Classic cars have a single coil, but many modern vehicles use one coil per cylinder. If your ride has a V8 under the hood, you could have eight separate coils. The monstrous Bugatti Chiron has 16. No matter how many you have though, a malfunctioning coil will almost certainly trigger the check engine light, but remember, if your car burns diesel, you have neither ignition coils nor spark plugs.
5. BAD SPARK PLUG WIRES:
As its name implies, a spark plug wire transfers electricity from the coil to the spark plug. Without it, the fuel and air mixture in the cylinders wouldn’t ignite. A vast majority of cars use a single wire per cylinder, but there are models - notably some older Mercedes-Benzes - with two spark plugs per cylinder, and consequently two wires.
Symptoms of bad spark plug wires include a rough idle, a noticeable drop in engine performance, and lower fuel mileage.
6. MASS AIRFLOW SENSOR FAILURE:
The mass airflow (MAF) sensor monitors how much air enters the engine. It’s a part of the engine-management system, so your car wouldn’t be able to adjust to changes in altitude without it. Symptoms of an MAF failure include a rough idle, trouble starting, and a sudden change in the position of the throttle pedal. Reduced gas mileage and stalling can also indicate an MAF problem.
7. VACUUM LEAK:
Every car has a vacuum system that performs a wide variety of functions. The brake booster is vacuum-operated, and the vacuum system also helps lower harmful emissions by routing the fumes as gasoline evaporates through the engine. If your car’s idle begins to surge or settles at an unusually high rpm, a vacuum leak could be the culprit.
8. EXHAUST GAS RECIRCULATION VALVE FAILURE:
The exhaust gas recirculation (EGR) system lowers the amount of nitrogen oxide that comes out of the car’s engine and helps it run more efficiently. It directs the hot exhaust gases back into the combustion chambers, which warms up the fuel and makes it easier to burn. It also reduces emissions.
9. DEAD BATTERY:
The battery is as simple as it is important; without it, your car won’t start, light up the road ahead, or charge your phone. Today’s batteries last much longer than before, and they’re maintenance-free.
10. THERMOSTAT:
Thermostat is a crucial component of engine cooling system.
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