The average cost of a repair due to a check engine light is $357, with parts and labor. The engine light can come on for a number of reasons. This a collection of sensors monitor’s your car’s emissions and critical components.
If you’re just driving normally and notice your light come on, it can be unnerving. This light may not immediately mean you have an emergency on your hands, though. You’ll need to take note of what your car is doing at that moment to determine if it is serious or not.
We know it can be frustrating to not know what to do without a background in cars, that’s why we made this guide. You’ll learn the most common engine light causes, what to do, and when to take action. Use this knowledge to ask a friend or family member for a second opinion before forking over hundreds or thousands in repairs.
Main Check Engine Light Sensors
The check engine light will detect problems with these car components, no matter what type of car you’re driving.
No, this sensor isn’t for measuring the amount of oxygen in the car’s cabin. The oxygen sensor is actually located in your car’s exhaust system. This helps maintain a proper mixture of fuel and oxygen in the engine.
When your car isn’t mixing oxygen with your fuel properly, it’s fuel efficiency nosedives. Your engine is essentially working harder to produce the proper amount of combustion for power.
When the oxygen sensor is no longer producing readings, then your check engine light will come on. This isn’t technically an emergency, but you should definitely take it in to get fixed as soon as you can.
Another sensor tied to your gas mileage that will monitor any leaks in your fuel system. If your gas cap isn’t screwed on tight, then it may trigger the check engine light, too. If your gas cap is on all the way, then it might not be producing a full seal anymore.
Over time, sometimes the caps can warp or crack, allowing gasoline to evaporate out. If the gas cap is actually still keeping its seal, then the problem may be more serious. A mechanic would need to check out the rest of your fuel tank system and see if there’s a bigger problem.
This is not something you want to fail if you’re worried about expensive repairs. The catalytic converter is strictly an emissions component of your car. When it is failing, it will cause your fuel efficiency to drop and your car to kick out more toxic exhaust.
There are a number of ways that the catalytic converter can be repaired, but if it is a complete loss, a replacement could mean spending up to $1,000. You can’t drive around without one because it is illegal and can cause even more damage to your car.
Mass Airflow (MAF) Sensor
Mass Airflow deals with your car’s air intake from the motor. As we have detailed earlier, the engine needs a precise mixture of air and fuel to achieve maximum combustion. Air that comes into the motor must be filtered to avoid introducing additional friction in the combustion chambers. This could result in serious damage to the engine.
The MAF sensor will come on when it detects that the air filter needs to be changed. Thankfully, this air filter sensor is very sensitive, so it won’t wait until it is completely filthy before triggering. Driving around with a dirty air filter will result in lower fuel mileage and a rougher ride.
This is a pretty common cause for the check engine light to come on. Your spark plugs should be changed regularly. How regular will depend on your car’s make and model. You can check the recommended maintenance schedule in your car’s manual.
Even if this isn’t the underlying cause for the engine light coming on, it’s important to practice preventative maintenance.
Connected to the spark plug, the ignition coil is what helps provide the spark from your spark plugs. This special coil converts electricity to the necessary voltage level for the spark plugs. When it fails to reach these voltages on a consistent basis, it will trigger your check light to come on.
Because this is such a delicate and important facet of your automobile, you should have a full check done on the ignition system.
When your battery starts to fail and stops charging properly, it will eventually trigger your light check, too. If you’ve had to get a jump for your car recently, then this might be a red flag for future problems.
This problem may even be tied to the alternator if it isn’t providing a constant charge. Both of these parts can be tested easily at any auto parts store or mechanic to see what needs to be replaced.
Differences in Light Checks
When your light comes on, it doesn’t tell you exactly what’s wrong, of course. But, how it comes on can determine the urgency of the situation. The engine light might come on briefly, stay on, or flash repeatedly.
If your light comes on and starts flashing continually, this is bad news. The engine light only flashes when it detects an emergency situation with your car. Usually, this means there was an engine misfire, which can quickly damage your catalytic converter.
Solid Lights and Brief Flashes
If your light comes on, but only for a few seconds, don’t freak out. It’s normal for the light to come on when you first start your car. Think of it as your computer’s sensors going through a checklist before getting the green light.
What most people are familiar with, though is the solid engine light that stays on. This will be where everything we have covered above falls into. If your car is running normally as far as you can detect, then you should be okay for driving a few miles with no repercussions.
Preventative Maintenance is Key
If you want to avoid the entire situation of diagnosing a check engine light, just keep your car maintained. Learn what it takes to prevent any fuel efficiency problems and reduce the cost of ownership.
People fear the costs associated with getting your car fixed in a pinch. The obvious solution here is to spend a little on preventative maintenance now and avoid bigger bills later. For more information on what you can do to maintain your car, read our easy-to-follow maintenance guides.
You don’t need to be a Greasemonkey to keep your car running smoothly.