What Are the Most Common Check Engine Light Issues?

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Fact: When the check engine light comes on it spells bad news. There’s something wrong under the hood. You feel frustrated and paranoid. And often confused about your next course of action.

Could be a loose gas cap triggering on the check engine light – easy fix.

However, it could also mean that your catalytic converter is faulty (expensive to repair), or the oxygen sensors are broken, among other car issues.

Correctly identifying these car issues is crucial. And GOFAR should be your little buddy.

It checks your car and reports on over 300 common car issues – In. Plain. English. Which means you can make timely repairs and avoid unnecessary expenses.

Keep reading to discover these common check engine light issues.

Failed Catalytic Converter

A catalytic converter is a simple yet costly part of the exhaust system that converts carbon monoxide into carbon dioxide in the combustion chamber

To prevent your catalytic converter from failing, observe regular car maintenance. Also, drive your car on the highway as often as is convenient to prevent clogging the catalytic converter.

If you hear unusual sounds while driving or observe discoloured smoke from the exhaust, then your catalytic converter is most likely failing. Ultimately, the check engine light will come on.

Related: Car Warning Lights Resource Centre

Faulty Spark Plugs and Wires

Spark plugs and wires should be replaced after a few years of use or when you hit about 10,000 miles. They are very affordable.

Spark plug wires transfer electricity from the coil to the spark plug. Without them, the fuel and air mixture in the cylinders can’t ignite.

When the spark plugs and wires are faulty, you’ll notice a decline in your car’s performance, engine misfire, poor fuel economy, or even a declining throttle response.

Failure to address these warning signs can lead to the damage of expensive car parts such as the catalytic converter.

Loose Gas Cap

Your check engine light might be because of a loose gas cap
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A loose gas cap is a common cause for the check engine light to come on. Maybe you’ve just come from the gas station and you forgot to fasten the gas cap properly. It sure is a simple mistake but it will trigger your check engine light.

But why? Because your gas cap is part of your car’s fuel delivery system. It prevents gasoline fumes from escaping the fuel tank. And also maintains the correct pressure in the whole fuel system.

Therefore, if your gas cap is loose after fueling up, tighten it and keep driving. The check engine light will go off after about 15-20 miles of driving.

If it’s faulty, buy a new one in your nearest store. Many are universal-fit gas caps and they don’t cost much.

Failing Mass Air Flow Sensor

The mass air flow sensor is a small car part that could easily fit on the palm of your hand yet is very costly to replace. It is a key component of the engine and onboard vehicle computer.

The mass air flow sensor regulates and measures the amount of air the engine receives and the amount of fuel injected. Without a mass air flow sensor, your car can’t adjust to changes in altitude.

A faulty mass air flow sensor can cause a drastic drop in your car’s fuel economy, cause poor engine performance, and car bucking/hesitation while in motion.

Faulty Alternator

An alternator converts direct current alternating current – DC to AC. Besides a car battery in good working condition you also need a good alternator with properly functioning electrodes.

The two work together to supply power to your car’s entire electrical system including the instrument panel, interior lights, the heating and AC controls.

In a nutshell, the alternator helps to regulate the electricity necessary for the proper operation of your car.

A faulty alternator not only turns the check engine light on, it also risks your safety. If the alternator fails when you’re driving, the car radio will go off, the interior lights will dim, and you will experience extreme difficulty in driving.

The reason being all power is lost. Power brakes and power steering won’t function properly anymore.

Ignition Coil Issues

An ignition coil generates electricity that the spark plugs use to ignite the fuel and air mixture in the cylinders.

The number of ignition coils in a vehicle depends on the car model. Classic cars have one ignition coil, but for modern cars it depends. A V8, for example, has 8 separate coils, the Bugatti Chiron has 16 ignition coils!

Regardless of the number of ignitions coils a car has, if one malfunctions, the check engine light will come on.

Some of the symptoms your car will exhibit are engine misfires and car hesitation under heavy acceleration.

However, if you have a vehicle that runs on diesel, then it has neither ignition coils nor spark plugs.

Aftermarket Alarm Issue

A well-functioning alarm system comes with peace of mind. On the flip side though, if you have an aftermarket alarm or one that’s hasn’t been installed properly, havoc can set in.

A faulty alarm system will drain the battery, prevent your vehicle from starting, and ultimately turn on the check engine light.

Can you really tolerate the alarm going off at night when you are fast asleep just because a cat or possum leapt on the hood? Probably not!

Therefore, if you’re experiencing similar issues with your car alarm, have it fixed, installed again, or replaced by a certified auto electrician.

Vacuum Leak

Has your car suddenly began to surge or settle at an abnormally high RPM? Chances are you have a vacuum leak.

You see, each car has a vacuum system that helps to lower harmful emissions by directing fumes while gasoline evaporates through the engine. The vacuum also operates the brake booster.

The vacuum hoses often dry and crack over time, more so when exposed to extreme hot or cold conditions, causing leaks. Cracked fittings and loosely fitted connections also cause vacuum leaks.

The good news is that the vacuum lines don’t cost much. But, the process of tracing the source of the leak is time-consuming.

Bad Oxygen Sensor

A faulty oxygen sensor leads to bigger problems with your car. Apart from turning on the check engine light, your fuel economy may drop by a whopping 40%. Which means expensive mileage and poor performance.

Although a car with a faulty oxygen sensor will continue to run, you need to have it replaced ASAP. Failure to do so can damage crucial parts such as the catalytic converter and spark plugs.

The causes of a bad oxygen sensor are internal leaks, or using contaminated fuel with high concentrations of ethanol or burning oil.

Exhaust Gas Recirculation Valve (EGR) Failure

The exhaust gas recirculation system helps the car engine run more efficiently by lowering the quantity of nitrogen oxide exiting the engine.

It also lowers the number of harmful emissions leaving the combustion chambers and also directs back the hot exhaust gases.

If your EGR valve gets clogged or fails completely, you can clean it up or replace it. It takes a short time and doesn’t require mechanical expertise.

Dead Battery

A good quality battery lasts longer and needs no maintenance. But without a battery, you can’t start your car! It’s that crucial.

If the car battery is faulty, you will notice the check engine light has come on. Just buy a new one or charge it if it’s still in good working condition.

Ideally, this should fix the issue and turn off the check engine light.

My Check Engine Light Is on – Now What?

The easy, common yet expensive route to take is to call your mechanic and book an appointment at the repair shop, right?

But here’s the good news: you can often skip going to the repair shop by diagnosing all your car issues yourself. Even if you’re not mechanically inclined.

How? The answer is an affordable little gadget called GOFAR.

Spend a few dollars on GOFAR, an OBD II scanner, download the GOGAR app to your phone and you are ready to play detective!

GOFAR will alert you when there’s a problem with your car so that you deal with it BEFORE it becomes expensive.

Better still, all the car problems will be explained in Plain English.

So, GOFAR Tells Me When I Should Fix My Car?

Affirmative! GOFAR monitors faults in your car every 2 seconds. It is a reliable and safe solution.

You will receive error codes on over 300 common issues with your car.

Check whether your car is compatible or learn more about understanding your dashboard symbols and car warning lights .

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