Engine failure in cars nowadays is quite unusual. But don’t think these modern cars won’t break down or pop up minor issues here and there. When such things happen (or before it happens), a check engine warning sign will light up to alert you. Check engine light in a car is often placed near the speed meter panel, in a bright yellow/orange colour. For some, this would mean nothing as long as the car runs smoothly. For some, this brings a sense of panic. Neither of these would help you solve this problem. The right thing to do is to take your car to your regular service center or the nearest repair shop and get it thoroughly checked. If you’re wondering what’s up with your car, here are eight possible reasons why your check engine light might be on.

1. Loose fuel filler cap

Before you lose your head in panic, keep in mind that a simple issue like loose fuel filler cap can pop up the check engine light. This is actually a common factor and something to check into if you have recently fueled up. Sometimes, it gets loose without anyone meddling about, so, when your check engine light pops up, make sure to check your fuel filler cap is tightly fastened.

2. Spark plug malfunction

Spark plugs are responsible to emit high volt electricity. It creates ignition for the combustion needed to burn up the air-fuel mixture. After some time, it is possible that one or more of these plugs could lose their sparking power. When this happens, your car might vibrate or shut down in a slow-moving traffic. When your check engine light pops up, your mechanic would look at the spark plugs for any sort of wear and tear.

3. Plug Wires need replacing

The spark plugs wires deliver the spark from the ignition coil to the spark plugs. A damaged or worn our plug wires will cause rough idle, a noticeable drop in engine performance, and lower gas mileage. This, on the other hand, causes the check engine light to light up.

4. Vacuum leaks

The vacuum system in cars has various functions. The brake booster is vacuum-operated and the vacuum system also helps lower harmful emissions by filtering the fumes as gasoline evaporates through the engine. As Malaysia can get pretty hot and cold sometimes, it is possible that the constant temperature change could damage it. Though finding the source of the leak is quite a work, the fix generally doesn’t cost much. So, if everything else under the hood seems to be in position, its time to check your vacuum system for leaks.

5. Oxygen sensor deterioration

This sensor detects if there’s oxygen released along with carbon dioxide through the exhaust. If there’s oxygen present, the oxygen sensor ensures that fuel ratio used for combustion is increased (so that the engine doesn’t knock or jerk). A car with a faulty oxygen sensor often doesn’t show any symptoms except for the high consumption of fuel. But in long run, it will deteriorate other components of the car (exp: spark plugs and catalytic converter) which will lead to a major fixture.

6. Catalytic Converter needs replacing

This part of the car is responsible for the carbon monoxide reduction into the environment. Catalytic converter transforms harmful carbon monoxide to carbon dioxide in an eco-friendly atmosphere. The good thing is, if you follow up with all your services on time, damaging this part is fairly unlikely. But if you have missed a few appointments here and there, when the check engine light pops up, your catalytic converter might need a replacement.

7. Mass Airflow Sensor needs replacing (MAF)

Unlike the oxygen sensor (that counts only the amount of oxygen at the exhaust), mass airflow sensor measures total air that enters the combustion chamber and determines the amount of air-fuel mixture needed for a smooth drive. Failure of this part will lead to spark park deterioration, oxygen sensor failure, and catalytic converter malfunction.

8. Exhaust gas recirculation valve failure

This mechanism is designed to reuse the exhaust gases to lower the cylinder temperature and nitrogen oxide emission. This valve is one of the main components that control the flow and recirculation of the exhaust gases. When there’s a fault in the valve, it can cause problems with the flow and operation of the valve system (which can lead to increased emissions and performance issues). Over time, this valve could get clogged or break down entirely. You would need a professional to clean or replace it so your best bet is to visit your mechanic as soon as possible.

Most importantly, do not panic when your check engine light glows up. Fairly, it’s your cars way of telling you that there could be a slight mishap happening within it. Also, do not ignore this sign as well. If sorted quickly, the damage won’t be big or cost you a fortune. You could avoid most of this by simply following your service schedules and sticking to one service center (as they would know your car better).