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5 Reasons Your Check Engine Light Might Be On


Most car owners dread the moment when the check engine light pops up on the dashboard. This is even scarier when they are on the highway or driving over long distances.

Truth is, the pop up can be attributed to a number of issues.

Most often it’s typically not an emergency or big repair. Any certified mechanic can be able to diagnose the problem rather easily.

Most modern day Mercedes-Benz have on-board diagnostic system that has code identifying the particular issue that caused the light to pop up. Let’s take a look at the common problems.

Replace Oxygen Sensor

This is the part that monitors the unburden oxygen from the exhaust and controls how much fuel is burned. A faulty sensor can’t provide the right data therefore causing a decrease in gas mileage.

Most cars have between 2-4 oxygen sensors and the code will tell you which one needs replacing. A sensor becomes faulty when it’s covered with too much oil ash and loses its ability to change oxygen and fuel mixture. A messed up oxygen sensor can lead to a burst catalytic converter which costs in excess of $2000.

Loose or Faulty Gas Cap

The gas cap is the most common cause of check engine light popping up. When it’s loose or cracked up, then it allows fuel vapour to escape and can mess up the whole fuel system.

This increases emissions and reduces gas mileage. When it indicates that the gas cap is faulty, pull over and retighten it. Examine the cap for any cracks or worn out edges. Continue driving for about 20 minutes and monitor if the engine light goes off. A typical gas cap costs about $3 only. A loose gas cap may not be risky but it leads to lower gas mileage.

Malfunctioned Catalytic Convertor

The work of a catalytic convertor is to reduce exhaust gases. It converts carbon monoxide and other toxic substances in fuel into harmless compounds. If it’s faulty or failing, the gas mileage reduces significantly. Most catalytic convertors stay in top shape through regular maintenance.

However, they can become damaged because of rusty spark plugs, or broken oxygen sensors etc. When it stops functioning the harmful gases will pass out through the exhaust into the environment. When a catalytic convertor fully deteriorates then it’s time to replace it.

Faulty Mass Airflow Sensor

This gadget tells the car computer to add the needed amount of fuel based on the air coming through to the car engine. That’s why when it’s faulty the emissions will increase, the gas mileage will decrease, and the car may stall.

This is one of the reasons the engine light pops up on the dashboard. The mass airflow sensor usually fails when the air filter is not replaced or when it wears out.

Faulty Spark Plugs and Wires

Another reason the engine light might pop up is because of spark plugs and wires. The spark plug seals the combustion chamber and provides the gab for initiating combustion in your engine. When they are failing they begin to misfire.

This is often marked by a little jolt when you start accelerating. Older spark plugs can be replaced after 25-30k miles while the newer ones can be replaced after 100, 000 miles. Still, plugs fail over time and there is little you can do about it.

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