Why Is My Check Engine Light On?
The check engine light (CEL) is a cause of stress for motorists everywhere. The car seems to be running fine, but that little orange engine illuminates the dash and ruins your mood. What could it be? It’s important not to ignore a check engine light, as sometimes it’s an indication of a major breakdown coming your way. However, if you pay attention to your vehicle’s maintenance and symptoms such as a check engine light, you can avoid a tow or a breakdown.
Top Five Reasons Your Check Engine Light Is On
There are multiple reasons your check engine light could illuminate, but if your car doesn’t have any obvious signs or symptoms of trouble, it could be one of these top causes.
1. Faulty Oxygen Sensor
One of the most common reasons for the check engine light to come on is a faulty oxygen sensor. A vehicle’s oxygen sensor measures the amount of unburned oxygen within the car’s exhaust system. Most often, the only noticeable symptom of a faulty oxygen sensor is the check engine light. However, if you don’t replace the oxygen sensor, you’ll likely lose fuel economy as your car will burn more fuel than is needed. Additionally, faulty oxygen sensors can cause damage to the car’s catalytic converters or spark plugs. If you suspect that your check engine light is due to a faulty oxygen sensor, be sure to take it into a reputable auto mechanic for diagnosis and repair.
2. Loose Gas Cap
Another common reason for the check engine light is a loose or malfunctioning gas cap. The gas cap may not seem as important as it is, but it seals the vehicle’s fuel system. Usually, there are no noticeable symptoms Without a properly functioning gas cap, hydrocarbons are released into the atmosphere and fuel may evaporate from the tank, costing you more in gas and increasing the number of trips to the pump.
3. Malfunctioning Catalytic Converter
The vehicle’s catalytic converter is responsible for converting carbon monoxide, a harmful byproduct of fuel combustion, into harmless carbon dioxide. Usually, there are no noticeable symptoms of a malfunctioning catalytic converter besides the check engine light. However, if you don’t address the issue, your vehicle will not pass an emissions test, your vehicle will run at a higher temperature, and you may lose fuel economy. Catalytic converter damage is usually the result of neglected maintenance, so be sure to follow the manufacturer-recommended maintenance schedule to avoid this issue.
4. Faulty Mass Airflow Sensor (MAF)
The mass airflow sensor is responsible for measuring the amount of air entering the engine to determine the proper amount of fuel needed to keep the engine running efficiently. While drivers may not notice anything different about their vehicle, if you don’t address a faulty mass airflow sensor, multiple problems could arise with your vehicle, including:
- Damage to spark plugs, oxygen sensors, and catalytic converters.
- Decreased fuel economy.
- Poor performance.
If your check engine light is on and you suspect a faulty mass airflow sensor, be sure to take your car into a reputable auto mechanic as soon as possible to diagnose and repair the problem.
5. Faulty Spark Plugs or Spark Wires
Another common issue that causes the check engine light to pop up is faulty spark plugs. The car’s spark plugs are responsible for igniting the air and fuel mixture within the engine’s combustion chamber. The spark wires deliver the spark from the ignition coil to the spark plugs. If the car’s spark plugs need replacement, the driver will likely notice the following symptoms:
- Reduced gas mileage.
- Lack of acceleration.
- Hard starts.
- Rough idling.
- Engine misfires.
- Check engine light.
Symptoms of faulty spark wires commonly include:
- Engine hesitation during acceleration.
- Check engine light.
- Engine surges.
- Engine misfires.
- Rough idling.
- Reduced engine power.
If you notice any of the above symptoms, you likely need your spark plugs or spark wires replaced. Take the vehicle into a mechanic as soon as possible!
Other Common Causes of the Check Engine Light
In addition to the above five most common causes of the check engine light, there are a few other things that could be causing that little orange light to come on, including:
Faulty Ignition Coil
If your vehicle’s computer detects an issue with its ignition coil, the check engine light may illuminate. Without a properly functioning ignition coil, your vehicle wouldn’t start. Be sure to address any ignition coil issues as soon as possible or you may find yourself stranded!
Incompatible Aftermarket Alarm
The check engine light may turn on if you’ve had an alarm system installed in your vehicle. Some aftermarket alarm systems can draw unnecessary power from the vehicle, causing the check engine light to illuminate.
Faulty Exhaust Gas Recirculation Valve
The vehicle’s exhaust gas recirculation valve is responsible for lowering emissions by recirculating exhaust back through the combustion process. If this part is faulty, the check engine light may illuminate and you may fail an emissions test.
How Can B&D Towing Help?
B&D Towing has been serving Concord and Contra Costa County for over thirty years. If you find yourself stranded due to a breakdown, call B&D Towing for emergency roadside assistance.