What Causes a Car to Show Engine Light?

Introduction

The engine light, also known as the check engine light, is a warning light on the dashboard of a car that indicates a problem with the engine or other parts of the vehicle. When the engine light is on, it means that the car’s computer has detected a problem and needs to be serviced. There are many different causes of an engine light, and some of the most common causes are listed below.

1. Loose or Faulty Gas Cap

One of the most common causes of an engine light is a loose or faulty gas cap. When the gas cap is not properly tightened, it can allow fuel vapors to escape from the fuel tank. This can cause the car’s computer to detect a problem and turn on the engine light.

2. Faulty Oxygen Sensor

The oxygen sensor is a sensor that measures the amount of oxygen in the exhaust gases. This information is used by the car’s computer to adjust the air-fuel mixture. When the oxygen sensor is faulty, it can cause the car to run rich or lean, which can lead to increased emissions and decreased fuel economy. In some cases, a faulty oxygen sensor can also cause the engine light to come on.

3. Faulty Mass Air Flow Sensor

The mass air flow sensor is a sensor that measures the amount of air that is flowing into the engine. This information is used by the car’s computer to calculate the amount of fuel that is needed. When the mass air flow sensor is faulty, it can cause the car to run rich or lean, which can lead to increased emissions and decreased fuel economy. In some cases, a faulty mass air flow sensor can also cause the engine light to come on.

4. Faulty Spark Plugs

Spark plugs are responsible for igniting the air-fuel mixture in the engine. When spark plugs are faulty, they can cause the engine to misfire. This can lead to decreased power and fuel economy, and it can also cause the engine light to come on.

5. Faulty Ignition Coil

The ignition coil is responsible for providing the spark plugs with the electricity they need to ignite the air-fuel mixture. When the ignition coil is faulty, it can cause the engine to misfire. This can lead to decreased power and fuel economy, and it can also cause the engine light to come on.

6. Faulty Fuel Injector

Fuel injectors are responsible for spraying fuel into the engine. When fuel injectors are faulty, they can cause the engine to run rich or lean. This can lead to increased emissions and decreased fuel economy, and it can also cause the engine light to come on.

7. Faulty Catalytic Converter

The catalytic converter is a device that helps to reduce emissions from the exhaust gases. When the catalytic converter is faulty, it can cause the engine light to come on.

8. Faulty Exhaust Gas Recirculation (EGR) Valve

The EGR valve is a valve that helps to reduce emissions from the exhaust gases. When the EGR valve is faulty, it can cause the engine light to come on.

9. Faulty Evaporative Emissions Control (EVAP) System

The EVAP system is a system that helps to prevent fuel vapors from escaping from the fuel tank. When the EVAP system is faulty, it can cause the engine light to come on.

Conclusion

There are many different causes of an engine light, and some of the most common causes are listed above. If your car’s engine light is on, it is important to have it diagnosed by a qualified mechanic as soon as possible. Driving with an engine light on can damage your car and lead to more expensive repairs down the road.