Can I Drive a Car with the Check Engine Light On?

Can I Drive A Car With The Check Engine Light On?It’s something that happens to all drivers at some point: the dreaded check engine light shows up on the dashboard. You’re just cruising along, minding your own business, then the sight of that light gives you chills. You’ll get the issue taken care of…eventually, but for now, there’s something you need to know. Can you still drive your car if the check engine light is on?

In most instances, yes, you can drive your car if the check engine light is on. As long as the vehicle is performing well. There are exceptions, such as a flashing check engine light. That can indicate an emergency. In that case, you’d need to stop driving and get your car to a mechanic immediately.

A check engine light can freak most drivers out, but a lot of the time, it’s nothing to get all worked up over. Keep reading, as we’ll tell you why the check engine light appears, how to make it stop, and when you can keep driving if you see it.

What Is The Check Engine Light?

First, before we get into the car problems your check engine light indicates, let’s share a quick definition of this light itself. Your check engine light, found on your dashboard, will light up in red or yellow. On some car models, the check engine light resembles a little engine. On others, it just says, “check engine.”

As part of your vehicle’s onboard diagnostics, the check engine light should stay off most of the time. When you see it illuminate, it means something’s wrong with your car. Despite the name, the check engine light doesn’t always specify a problem with your engine. Instead, it’s often an issue with the sensors and other components of your car.

Should You Drive Your Car If The Check Engine Light Is On?

Okay, so you’re driving one day, and the check engine light comes on. That’s strange, you think, primarily because your car is otherwise operating just fine. The brakes stop when you press on the pedal, the steering moves with you, and the car runs without a clunk or bounce.

You’re not one to ignore vehicular problems as they crop up, but is this a problem? Well, it can be. In the next section, we’re going to explain what makes the check engine light flash on your dashboard. For now, we’ll say that while the check engine light does mean there’s a problem of some kind, not always is it a severe, must-stop-now kind of problem.

If you're a fan of The Big Bang Theory, then you probably know this is a constant source of worry for Sheldon when the Check Engine light is on in Penny's car.

So, who's right? Penny or Sheldon? Is this really a problem?

Of course, you must use your common sense. If you notice an odd odor or your vehicle is performing under par, and you see the check engine light, then you don’t want to wait. Get the problem addressed by a mechanic.

Also, make sure you pay attention to the light and what it’s doing. If the light illuminates consistently, then you can afford to wait before getting the car seen by a pro. It’s when your check engine light flashes on and off that you have an emergency on your hands. You’d want to schedule an appointment with your mechanic immediately.  We also wouldn’t recommend driving your car when the check engine light flashes.

So yes, while you’re free to continue driving if your check engine light is on but not flashing. Don’t get too lax. There’s still something wrong with your car. Don’t ignore the check engine light indefinitely. What starts as a small issue can get bigger. While you can maybe wait a few days before seeing your mechanic, don’t put off your appointment for weeks and weeks. You may end up paying for it later.

What Would Make The Check Engine Light Come On?

Like we said before, your car could run as good as the day you bought it, and yet the check engine light is still there. For a moment, you wonder if your car has glitched. Then you hop in the driver’s seat the next day, and you still see the light.

Why? Here are some reasons your check engine light could appear:

  1. Problems with the spark plugs or wires
  2. Mass Airflow Sensor
  3. Broken Catalytic Converter
  4. Misplaced Or Damaged Gas Cap
  5. Oxygen Sensor Issues

Problems with the Spark Plugs or Wires

The first culprit for the check engine light? Spark wire or plug problems. When your car works fine, your spark wires and plugs set alight a combination of fuel and air within your vehicle’s combustion chamber. This produces a spark that moves from the combustion chamber to your car’s plugs via ignition coils.

If your spark wires or spark plugs fail, it could affect the catalytic converter and oxygen sensors, as well. The ignition coils could end up ruined, too. Another sign that it’s your spark wires or plugs beside the check engine light is reduced fuel performance.

Mass Airflow Sensor

We mentioned before that the check engine light is triggered by sensor issues, including those with your mass airflow sensor. This sensor manages engine airflow levels. If your engine gets too much air, it won’t work as well. Your oxygen sensor, catalytic converter, and spark plugs can also get screwy.

Broken Catalytic Converter

One of the most critical components of your vehicle, the catalytic converter makes carbon dioxide from carbon monoxide. Your emissions will become downright dangerous the longer a catalytic converter problem persists, so don’t wait to get this one fixed.

Misplaced Or Damaged Gas Cap

Your fuel system has a gas cap, but sometimes this cap happens to go missing. In other cases, it can loosen and fall off, and it may even end up broken. In all those situations, your car’s gas evaporates more than it should. You’ll find yourself filling up at the pump more regularly than you ever did before.

 Oxygen Sensor Issues

We’ve mentioned the oxygen sensor a few times already, but what does it do? Good question! This sensor manages how much oxygen your fuel system has, especially unburned oxygen. If the sensor goes haywire, the catalytic converter and spark plug can suffer the consequences. Also, your fuel economy will tank.

What Does a Flashing Check Engine Light Mean?

To reiterate, a flashing check engine light is severe. If yours blinks for over six seconds, that’s not good.  What exactly is wrong with your vehicle?

It can mean that your engine has misfired. This means the fuel-air mixture in one of the cylinders has not ignited correctly. When this happens, your motor may run rough or not at all.

As you may have guessed, an engine misfire is no laughing matter. You need to see a mechanic ASAP.  A professional can address an engine misfire. If you ignore the misfire, you may severely damage the engine.

The timing of the engine may also be off. All vehicles have a timing belt or chain. This helps drive the pistons and time the strokes of the firing in the cylinders. These can wear out and fail. If this happens, your check engine light can flash, or your car may stop running.

How Do You Turn The Check Engine Light Off?


The best way to stop seeing the check engine light is to get the issue fixed. If you do that, then the light should disappear on its …most of the time. In certain annoying cases, the light can persist even when your car is running better than ever.

You can always go back to your mechanic and ask them to take care of it, but you can also turn the check engine light off yourself. Here are a few ways to do that.

Run an OBD Code Reader

Since the system that dictates when your check engine light goes on is all computerized, and onboard diagnostics or OBD code reader can help quite a bit. The original equipment manufacturer limited OBD-I readers, but most  ODB-II readers work regardless of manufacturer.

You can use your OBD code reader by connecting it to your car’s OBD port. Didn’t know you had one? Check underneath your dashboard near your floorboard. Depending on the vehicle you have, you could have to detach the fuse box door and then get to the OBD code reader port that way.

Let the reader run. Do you get any error codes with your reading? If so, erase them, but only if the issue is taken care of. Then, using the code reader, you can reset your pesky check engine light. It should stay off from there.

Not all vehicles have these ports! If your vehicle is older, you will have to have the problem diagnosed.

Disconnect Your Battery and Reset It

Your car battery could get in the way of your check engine light turning off. To fix the issue, open your car’s hood and look for the battery. With a wrench, separate the battery’s negative power cable. Give it 15 minutes to reset. Carefully reconnect the battery.

Now start your car again and see if the check engine light has disappeared. It should have.

Run the Engine Three Consecutive Times, Turning It On and Off Quickly

You can also skip the part with taking your battery apart and just run the engine thrice by turning the car on and then off. Each time, you want to let the car run for only a second. Turn it off for just as long and then do it again and then one more time. If done correctly, this should reset the check engine light.

How Many Miles Should You Drive a Car After Resetting the Check Engine Light?

Yet a fourth option you have for making the check engine light go away is to drive. If you truly got the problem with your car fixed, then the light should turn off on its own, no finagling required on your part.

This may take some time, as the light might not disappear until you reach 50 miles. In some instances, you have to drive 100 miles. A good rule of thumb is this: if, after 100 miles or three days, the light still won’t go away, it probably won’t on its own. You probably have to reset it following the steps above manually.

Your car’s check engine light lets you know something is wrong. If your car runs fine, then you can get away with waiting a day or two before seeing a mechanic. If the light is flashing off and on repeatedly, do not hesitate to get the issue diagnosed.


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