The 5 Most Common Check Engine Lights

The 5 Most Common Check Engine Lights

And What They May Be Telling You



We know it’s never a good feeling when you see your check engine light come on. And while that little red light could mean an expensive repair, sometimes, it may just be a small, simple fix. Either way, it usually means you’ll need an expert’s help.


So, what should you do when your check engine light comes on? Anytime one of your check engine lights comes on, it’s a warning sign from your car’s computer that there’s something wrong. And for that reason, our experts recommend bringing your car in and letting us check your engine right away. Although our answer seems obvious, many people, unfortunately, do nothing – about 10% of all drivers to be more exact. And of those drivers, about half have ignored the issue for three or more months.


Those who ignore their check engine lights probably have several reasons for putting off the repair (i.e. money, time or convenience). However, it’s definitely not the route we suggest. Because not only are they risking your and other drivers’ safety, but ignoring those warning lights only leads to larger, more expensive engine repairs down the road.


Most of the time, when your check engine light comes on, it’s one of 5 common causes, several of which are a small, simple fix. So, starting at number 5, here they are:


5. Old, Worn Spark Plugs & Wires:

Your spark plugs close off the combustion chamber and create a gap for a spark to jump across and initiate combustion. But when your spark plugs start malfunctioning, they misfire, which might lead to little jolts during acceleration.


Cause: Generally, most spark plugs in cars manufactured before 1996 should be replaced about every 25,000 – 30,000 miles. Those in cars produced since then can last up to 100,000 miles. The bottom line is that spark plugs simply just fail over time.


Solution: Visit your local City Garage and let our experts replace your spark plugs and wires immediately. It’s really a pretty cheap and simple fix, and you’re engine will perform much better.


4. Broken or Faulty Mass Air Flow Sensor:

Your mass airflow (MAF) sensor communicates with your car’s computer and tells it how much fuel to add based on the air coming through to your engine. But when your mass airflow sensor starts failing, it can cause an increase in emissions, a decrease in gas mileage and your car to stall.


Cause: Typically, most mass airflow sensors stop working because of either an improperly installed or an old, dirty air filter.


Solution: Stop in at your neighborhood City Garage and let our experts inspect and replace your MAF sensor and air filter. As a preventative measure, our experts recommended replacing your air filter at least once a year. However, depending on where you live, you may need to replace it more often, especially if you’re living in a dusty, rural area. But when you bring your car in to City Garage, our experts will be able to tell you when it’s time for a new air filter.


3. Broken or Damaged Catalytic Converter:

Your catalytic converter helps reduce your engine’s exhaust gases by converting carbon monoxide and other toxic pollutants into harmless emissions. But when your catalytic converter stops working, it not only stops converting carbon monoxide into less harmful emissions, but causes a decrease in gas mileage as well as an inability to increase your speed as you accelerate.


Cause: Usually, your catalytic converter shouldn’t fail as long as you’ve been routinely following your car’s recommended maintenance schedule. Broken oxygen sensors or old, worn spark plugs are generally the main cause of catalytic converter failure.


Solution: Bring your car into your neighborhood City Garage and let our experts fix you up. Our experts suggest stopping in as soon as possible because if your catalytic converter completely fails, your car won’t continue running for long. Plus, you’ll have much lower gas mileage until then.


2. Loose or Bad Gas Cap:

Your gas cap plays an important role in your car’s emission control system. But when it’s loose or cracked, it lets fuel vapors escape, which can really throw your fuel system. And ultimately, it leads to a decrease in gas mileage and an increase in emissions.


Cause: Usually, when your gas cap light comes on, it means fuel vapors are leaking due to either a loose or cracked cap.


Solution: As long as your car isn’t jerky or driving any differently when your light comes on, our experts recommend pulling over and checking your gas cap. Tighten it and look over it for any visible cracks. Then, see if the check engine light turns off once you start driving. If your light still stays on after you’ve started driving, we suggest you stop in at your local City Garage and let our experts inspect and replace your gas cap.


1. Broken or Faulty Oxygen Sensor:

The number one cause for your check engine light coming on is due to a faulty oxygen sensor. Your oxygen sensors monitor the oxygen content circulating through your engine’s exhaust system and help your car’s computer to adjust the air-fuel mixture to match your current driving conditions. But when your O2 sensor becomes broken or faulty, it stops providing the right data to your car’s computer, which directly affects your engine’s performance and can cause a decrease in MPG by up to 40%.


Cause: Eventually, as your car gets older, your sensors become covered in oil ash, reducing their ability to regulate your oxygen and fuel ratio. Faulty sensors not only lead to paying more at the pump, but your car won’t pass an emissions test at inspection time either.


Solution: Call or book an appointment online at your neighborhood City Garage and let our experts inspect and repair your broken oxygen sensors. Our experts recommend coming in as quickly as possible because holding off on this repair can eventually lead to a broken catalytic converter, which will be a much more expensive fix.


While there are several potential problems that your check engine light could be pointing to, these 5 are the most common.


So, if we haven’t already stressed this enough, when warning lights show, be sure to stop in and see us ASAP. In the end, it’ll not only save you time and money, but keep you on the road, safely with peace of mind.


Is your check engine light on? If your answer is yes, be sure to book an appointment at any of our 16 locations throughout the DFW Metroplex today.