Why Is Your Check Engine Light On?

Having your car break down in the middle of traffic or during a snowstorm is probably the last thing you want to happen. You can avoid these unwelcome situations by paying attention to your vehicle and conducting regular maintenance checks. So, when your check engine light is on, how do you know what’s causing it? Here are the top five reasons for check engine lights to turn on:

1. One of the most common reasons for an engine warning light to come on is the oxygen sensor. The oxygen sensor measures the unburned O2 in the exhaust system of your vehicle. You may need to replace your vehicle’s sensor or risk having poor fuel economy. If the O2 sensor isn’t functioning properly, your engine will consume more fuel than necessary. A faulty sensor such as the O2 sensor can also damage the integrity of your vehicle’s spark plugs and catalytic converter.
2. Another possibility is that your gas cap may be loose or missing. This is relatively easy to fix and you don’t want to let it go unchecked. Your gas cap prevents gas from evaporating and maintains pressure within the gas tank. Without a functioning gas cap you could find yourself making more trips to the pump than necessary.
3. There could be a problem with your catalytic converter if your check engine light is on. The catalytic converter is important because it converts harmful carbon monoxide into carbon dioxide. If you don’t have the converter fixed or replaced, your vehicle won’t pass an emissions test and it will have reduced fuel economy.
4. If your mass airflow sensor (MAF) isn’t working properly, it will also cause your check engine light to turn on. The MAF sensor measures the amount of air entering your engine, which impacts how much fuel is needed for your engine to function. If left unchecked, your faulty MAF sensor could cause damage to other sensors such as the O2 sensor (see #1).
5. You may need to replace your spark plugs or plug wires if your check engine light is on. The spark plugs and plug wires ignite the fuel in the combustion chamber. You should have your spark plugs replaced if you don’t want to risk poor performance, reduced fuel economy, and damaging other essential parts of your vehicle.

No matter what the reason for your check engine warning light to come on, you should have your vehicle checked regularly to avoid dangerous situations.