Top Ten Reasons Why Your Check Engine Light is On

check-engineIs your check engine light showing? Can you tell what the cause is? What comes to mind is the garage and parting with some money. Some fixes you can do by yourself although but for some you still have to visit your car specialist. One or several of these reasons might be the cause of the engine light to show.

Instead of spending money to have a local mechanic take a look, get yourself a good car code reader and the best multimeter you can afford. These will be two of the best investments you will ever make for your car.

1. Defective or broken oxygen sensor

An oxygen sensor determines the amount of oxygen in the engine and helps the computer to inject the required amount of gas into the engine. If it’s faulty or damaged the computer can’t tell the amount of fuel required and in most cases, it injects more fuel affecting the fuel consumption sometimes as much as 40% more than average.

2. Loose or faulty gas cap

If the gas cap is not sealed tight vapor will evaporate from the gas tank, and this interferes with the fuel system efficiency which alerts the driver using the engine light. The range will decrease and emissions increase.

3. Faulty catalytic converter

A catalytic converter is used to lessen harmful exhaust gasses. It fails if something else breaks such as the oxygen sensors or defective spark plugs. This triggers the engine light and reduces the gas mileage. Unfortunately, catalytic converters are not cheap. According to Car Treatments, installing a new catalytic converter (including labor) can run you anywhere from about $615 to $2,200. Those with dual exhausts can expect to pay even more.

4. Broken Mass airflow sensor

The mass airflow sensor informs the vehicle’s computer to dispense the appropriate amount of gas based on the air flowing through the engine. It fails when the air filter is not replaced or fitted incorrectly. It decreases the range, increases the emissions or the car might shut down completely.

5. Faulty spark plugs or spark plug wires

Spark plugs initiate combustion and if they wear out or are defective the car might have a hard start or the ride will be jerky especially during acceleration. If the spark plug wires are naked or faulty, they should be replaced. When ignored the car might stall.

6. Broken alarm system

Car alarms that are installed after the cars are manufactured should be done by an expert because a wrong connection might affect the engine management system prompting the engine light. If the car already has the alarm, it should be properly mounted or removed entirely.

7. Faulty thermostat

A thermostat keeps the engine cooling functions in check. If it is defective, it might mismanage the engine and cause it to overheat, to avoid that the engine light alerts the driver. Common symptoms of a bad thermostat include: engine overheating, unexpected interior temperature changes, and noises coming from the radiator area.

8. Faulty Exhaust gas re-circulation

The exhaust gas re-circulation pushes back exhaust gasses through the combustion chamber which increases the gas mileage and reduces pollution of the environment and when it fails it does the exact opposite. The primary cause of failure is a broken ERG valve or a blocked system which should be cleaned or replaced.

9. Defective battery or a bad battery charging system

Most of the new cars engine management system are relying on the battery so when the battery or the charging system fails the whole engine will not function properly.

10. Bad ignition coil

The coil steps up the voltage of the battery and uses it to produce sparks using spark plugs which initiate the combustion. Poor maintenance, use of substandard spark plugs or old coils might be the cause of the failure.

Most of these glitches can be avoided by regularly servicing and diagnosing your car to fix them before they disable your vehicle.

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