It usually happens on your way to work or when you have a list of errands to run and you are miles from home. All of a sudden POW your engine light comes on.
“Oh no” you think to yourself “my check engine light is on”. “Is my car going to make it? How much will this cost?” All of these questions start flooding your brain.
Your engine light can come on for a ton of reasons. Luckily, keeping up with your vehicles regular scheduled maintenance intervals can prevent most of the reasons the check engine light would come on. But if it does pop on most of them are fairly easy to diagnose and repair if you see to them in a timely manor.
Here are 5 of the most common reasons for your check engine light to come on.
1. Oxygen Sensors (O2 replacement)
An oxygen sensor monitors how much fuel your vehicle is burning. A faulty sensor will not allow the correct data to be sent the computer and will cause a your car to become less gas efficient.
What causes it? Over time, the sensors can get covered in debris, which then reduces the sensors ability to change the oxygen and fuel mixture. A faulty sensor not only reduces gas mileage, it also will increase emissions.
What you should do? An oxygen sensor can be a fairly easy fix if you can catch it in time. Leaving one go for long periods of time will eventually result in a busted catalytic converter, which can be very expensive. It is best to address the problem right away to avoid other more expensive issues arising.
2. Loose or faulty gas cap
You wouldn’t think something as simple as a gas cap would be that important, but it is. When it’s loose or cracked, fuel vapors leak will out and can confuse the whole fuel system. This will cause a reduction in gas mileage and increase in emissions.
What causes it? When you get an error pointing to the gas cap it will mean fuel vapors are leaking out of your cap. This can happen if the cap is either cracked or just wasn’t tightened well enough.
What you should do? If your car is still driving normal when the check engine light comes on you should pull over, retighten the gas cap, and take a look at the cap to see if it has any cracks in it. Continue driving and see if the check engine light turns off. While not car-threatening, it’s good to take care of this right away to improve gas mileage.
3. Replace catalytic convertor
The catalytic convertor functions to reduce exhaust gases. It converts carbon monoxide and other harmful materials into harmless compounds. If your catalytic convertor is failing, you’ll notice a decrease in gas mileage or your car won’t go any faster when you push the gas.
What causes it? Catalytic convertor failure can be easily prevented if you’re keeping up on regular maintenance. The main cause of failure is connected to other items on this list, including a broken oxygen sensor or deteriorated spark plugs (we’ll get to those in a second). When it fails, it stops converting carbon monoxide into less harmful emissions.
What you should do? If your catalytic convertor fails completely, you eventually won’t be able to keep the car running. Your gas mileage will also be terrible, so you should try and fix it as soon as you can. Unfortunately, the average replacement cost is around $2,000 and you can’t do it yourself unless you’re an experienced mechanic.
4. Replace Mass Air Flow sensor (MAF sensor)
The mass airflow sensor tells the vehicles computer to add the proper amount of fuel based on the air coming through to the engine. A faulty one can increase emissions, cause the car to stall, and decrease gas mileage.
What causes it? Most mass airflow sensors fail because of an air filter being improperly installed or never replaced. You can drive for a few weeks or even months with a broken MAF sensor. You will notice a decrease in gas mileage and over time the car will eventually start stalling a lot.
What you should do? It’s not terribly difficult to do on your own, but the process is quick enough you may want to let a mechanic handle the project in case the sensor doesn’t end up being the issue. You should check your manual for regular scheduled intervals for the replacement of your air filter to help prevent the airflow sensor from failing.
5. Replace Spark Plugs and wires
The spark plug seals the combustion chamber and provides a gap for a spark to jump across and initiates combustion in your engine. When the plugs are failing, the spark plugs misfire. You’ll feel a little jolt in your car’s acceleration when this happens
What causes it? Over time spark plugs get dirty and corroded causing your engine to misfire.
What you should do? Get them replaced right away. It’s easy and cheap and your car will run better for it. Since this is part of your vehicles regular maintenance, your manual will have scheduled recommendations for replacing them.