Harnessing Expert Insights: Unraveling Check Engine Light Causes and Remedies for Optimal Vehicle Performance
The Check Engine Light, the Malfunction Indicator Lamp (MIL), or what on some cars is the Service Engine Soon Light. While it goes by several names, it’s a light that all drivers dread seeing illuminate on their dashboards. Almost everyone has had the experience of having to deal with his or her Check Engine Light coming on at least once.
What makes the Check Engine Light especially annoying is that there’s no one specific reason for it to light up. With many other dashboard warning lamps and messages, the cause is typically simple and clear. If the Low Oil Light is on, for example, you’re probably low on oil. Or, if the Maintenance Required Light comes on, it’s time for an oil change or other routine service.
With the Check Engine Light, though, it’s not so clear. Any one of a number of different causes could be responsible for the light turning on. Some of them are inexpensive and relatively easy to fix. Others are far more complex, serious, and require urgent attention. To take some of the fear of the unknown out of the Check Engine Light, it’s worth taking a little time to understand the range of possible reasons why the light kicks on.
Common Causes for the Check Engine Light
The good news about the Check Engine Light turning on in your vehicle is that there’s a pretty good chance that it doesn’t mean disaster. Many of the common causes for the Check Engine Light are relatively minor issues. Most aren’t very expensive to fix.
However, in order to fix the underlying problem, one has to be able to diagnose what it is. That’s not always easy to do if you’re not experienced with working on cars. Most times, when the Check Engine Light turns on you won’t immediately observe any difference in your vehicle’s performance. It’s going to be hard to rule out any possible issue without investigating more deeply.
Given that you won’t be able to immediately know what’s wrong, it’s useful to at least know the range of possible causes of the Check Engine Light. Being informed as to the likely possibilities gives you a head start in trying to diagnose the actual problem. Below are some of the most common Check Engine Light causes we see here at Temecula Auto Repair & Transmission.
Faulty Catalytic Converter
Let’s start with one possible worst-case scenario. Your catalytic converter may be faulty. The catalytic converter is a crucial part of the exhaust emissions system. If it begins to fail it will cause your Check Engine Light to light up. Out of all the possibilities, this is the one that would potentially be most expensive to repair. Typically catalytic converters cost over $1,000 to repair or replace on average. A failed catalytic converter is also necessary to address quickly.
The catalytic converter is responsible for breaking down poisonous and toxic exhaust gasses such as converting carbon monoxide into harmless gasses and compounds. If the catalytic converter isn’t working, you won’t pass your Smog Check, and your vehicle’s general performance could degrade significantly. You’ll sometimes see poorer acceleration, general performance deficiencies, and gas mileage may also suffer.
This may all paint a gloomy picture. However, you should be aware that faulty catalytic converters happen almost exclusively because the owner of the vehicle isn’t keeping up with routine maintenance. In fact, many of the other reasons that the Check Engine Light comes on can lead to a breakdown of the catalytic converter over time. This is why it’s important to come see us right away whenever the check engine light comes on. By being vigilant about your vehicle’s well-being and getting regular maintenance, you’ll dramatically reduce the odds of having a catalytic converter fail.
In the state of California, the second most likely reason the Check Engine Light comes on is due to a problem with the catalytic converter.
Damaged, Missing or Loose Gas Cap
From the most serious possibility, we move to the least costly reason for the Check Engine Light to turn on. If the gas cap isn’t keeping pressure in the fuel tank, this will cause gasoline fumes to escape the tank. This in turn, will trigger the Check Engine Light. If the Check Engine Light comes on, this should be your number one starting point in trying to figure out the issue.
First, undo and re-fasten your gas cap, and then turn on the engine again. Drive the car for a bit, and see whether the Check Engine Light remains on.
In comparison with most of the other issues possibly causing the Check Engine Light to go on, an issue with the gas cap is the best-case scenario. A faulty or loose gas cap is usually something you can fix easily and quickly.
Malfunctioning Spark Plugs and Wires
Another possible reason for the Check Engine Light coming on are faulty spark plugs. A spark plug’s function is to give a spark to initiate the engine’s combustion process. If a spark plug goes bad or wears out, it can cause the engine to misfire. An engine misfire will always trigger the check engine light to come on. A telltale sign that a spark plug has gone bad is a minor jolt when you accelerate your vehicle. Other signs of misfiring spark plugs are trouble starting your car and reduced fuel efficiency. A rough engine idle is one more sign that can point to a misfire.
If your spark plugs are faulty, this is an issue you want to resolve as soon as possible. In addition to trouble with acceleration and fuel economy, bad spark plugs can lead to additional damage to your engine over time.
Malfunctioning Oxygen Sensor
The oxygen sensor regulates the mixture of fuel and oxygen in your engine. Over time the oxygen sensor can become fouled with ash or other exhaust build-up. When this happens, its ability to regulate the mix of oxygen and fuel begins to diminish or fail. This can cause the Check Engine Light to turn on. In addition, when the oxygen sensor isn’t working, you’ll experience increased emissions and lower fuel economy.
One very important thing to know is that driving a vehicle with a damaged or faulty oxygen sensor can cause damage to the catalytic converter. It’s considerably less expensive to have an oxygen sensor fixed than a catalytic converter. So, it’s another reason to deal with a Check Engine Light as soon as possible, in case it’s an oxygen sensor problem.
It’s worth noting that the number one cause of a Check Engine Light in the state of California is a problem with the oxygen sensor.
Malfunctioning Mass Airflow Sensor
Another possible culprit for a lit-up Check Engine Light, is a problem with your mass airflow sensor. The mass airflow sensor sends information to and from your vehicle’s computer. This electronic communication is to synchronize fuel in your engine based on current airflow into the engine. If your vehicle has an old air filter or a poorly installed air filter it can cause damage to the mass airflow sensor.
If this happens, you’ll experience higher emissions and poor fuel economy, similarly to many of the other causes of the check engine light. You’ll notice that several symptoms of the various causes of the Check Engine Light are nearly identical. This makes it difficult to diagnose the problem easily.
The biggest preventative thing you can do to avoid trouble with the mass airflow sensor is to replace your air filter once a year or more frequently. By doing so, you decrease your risk of having problems which can be considerably more costly down the line.
Less Likely Check Engine Light Issues
The catalytic converter, gas cap, spark plugs, oxygen sensor and mass airflow sensor are the most likely reason for a Check Engine Light coming on. In most cases, it’s going to be one of those five root causes. However, there’s a chance that it’s none of the above, and instead one of a handful of other less likely problems is causing the light.
A broken or malfunctioning thermostat or ignition coil are less common causes. Problems within the evaporative emissions (EVAP) system can also cause the Check Engine Light to turn on. While these tend to be less common, it’s impossible to rule these out as the cause without investigating further.
A Flashing Check Engine Light
Briefly, it’s worth talking about the rare possibility of a blinking Check Engine Light. This is an uncommon occurrence, but also marks a much more serious problem. So, it’s good to be aware of it.
With all of the above-discussed problems, the Check Engine Light will typically not blink. It will just be a solid, unchanging warning light. If the light is not blinking, this is a problem you need to address at some point, preferably as soon as you’re able. However, a solid Check Engine Light is not an immediate danger to your vehicle. In other words, you can drive your vehicle for a little while if you need to.
That isn’t true if the Check Engine Light is blinking. If that’s the case, this means your engine is having a serious problem. One possible cause of a blinking Check engine Light is that fuel may be inside the catalytic converter itself. If this happens, driving the vehicle risks significant damage. There’s also a risk of your vehicle breaking down or, worse, catching fire due to raw fuel in the exhaust.
If the light is blinking, it’s best to safely pull over and tow the car in to us immediately.
Self-Diagnosing Using Check Engine Codes
When Free Is Too Good To Be True
You may be aware of a service provided by certain auto parts stores where they’ll give you a free reading to determine the code associated with your Check Engine Light. The store will then sell you parts associated with that code to fix the Check Engine Light to avoid going to a professional shop. For example, retrieve a code most associated with an oxygen sensor issue. Then the store will sell you an oxygen sensor.
This method of fixing your Check Engine Light will sometimes be successful, but it’s not guaranteed by any means. You should know trying to self-diagnose using the check engine codes can lead you astray. This could cause you to waste money on unnecessary parts.
What makes this method less than foolproof is that check engine codes don’t always match up with the exact root cause of the Check Engine Light on. As you probably noticed from reading the common causes of the Check Engine Light, many of the systems and parts responsible are complicated and sometimes intermingled with one another. As a result, a code that ‘usually’ means one part is faulty may in fact have a different root cause of the real problem. Additionally, there are other components directly involved in these systems. For example, faulty oxygen sensor wiring will store an oxygen sensor code as much as a faulty oxygen sensor would.
So, you could encounter a scenario wherein you get your code readout and spend a decent amount of money on a part that’s supposed to fix your problem. You install the part, and sometimes the Check Engine Light stays on. Or maybe it turns off, but then comes right back on in a day or two.
A Proper and Thorough Evaluation Is The Best Approach
The way to guarantee that the problem causing your Check Engine Light to come on is fixed is to bring your vehicle in for a proper evaluation by our professionals. We have the right tools and know-how to correctly diagnose the real issue. We’ll then make recommendations that will ensure you’re back on the road no longer troubled by that annoying Check Engine Light. If you need help with a Check Engine Light or any other car issues, Book An Appointment today.
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