Can AutoZone tell me why my check engine light is on?

Author: Clementine Fay  |  Last update: Monday, October 6, 2025

If you see a warning light, come to AutoZone. Fix Finder reads information from the Check Engine, ABS, and maintenance lights. The test often takes less than a minute once the reader is plugged in.

Can AutoZone tell you why the check engine light is on?

AutoZone will lend you an OBD-2 reader to plug into your car's computer port (usually located by the gas/break pedals) that will give you a diagnoses as to why your check engine light is on once you bring it back to them.

How do I find out why my check engine light is on?

The most foolproof method to check the engine light is to read the diagnostic code in the car's internal computer. If you have experience working with cars, you can do this at home with an OBD-II scanner.

Does AutoZone read check engine lights for free?

Visit Your Local AutoZone Store for Free Fix Finder Service

AutoZone offers a complimentary Fix Finder service that efficiently diagnoses warning lights, including Check Engine, ABS, and maintenance indicators. Simply visit your nearest AutoZone store when a warning light appears on your vehicle's dashboard.

Can AutoZone tell me what's wrong with my engine?

Autozone doesn't do diagnostics. All they do is read codes. Getting a code isn't a diagnostic. Getting the code read is the equivalent of getting your blood pressure taken. It gives you an idea that something is out of whack, but it doesn't tell you the cause.

Why Is My Check Engine Light On? Easy Fix!

How much is a diagnostic test at AutoZone?

The free test takes less than a minute, and you'll get an easy to understand report printed and emailed.

What is the most common check engine code?

The Most Frequent Diagnostic Codes for Check Engine Lights & Their Meanings
  1. Engine Misfire: P0300 to P0305. ...
  2. Emissions Issues: P0400 to P0499. ...
  3. Failed Oxygen Sensor: P0150 to P0175. ...
  4. Catalytic Converter Problems: P0420 to P0434. ...
  5. Mass Airflow Sensor Damage: P0101 to P0104 & P010A to P010D.

Can I diagnose a check engine light myself?

Diagnosing your check engine light

Buy an OBD-II scan tool: There are affordable tools that allow you to run a diagnosis yourself.

Can low oil cause a check engine light?

Low Oil and Check Engine Light

However, low oil pressure, which can be caused by low oil levels, can be a reason for the check engine light to turn on. Low oil pressure can seriously interfere with your car's performance and disable your vehicle if not addressed immediately.

Why is my check engine light on but my car runs fine?

Check engine lights can turn on for a number of reasons. Some can be minor problems such as tightening the gas cap, and others can be serious problems like engine issues. If your vehicle is running fine, the check engine light may signal a minor issue, but it is best to visit a mechanic to make sure.

How can I check my check engine light code without a scanner?

Method 1: Use Your Odometer Reset to Check Engine Light Codes
  1. Step 1: Press and hold the odometer's reset button.
  2. Step 2: While holding the odometer's reset button, press and hold the odometer's trip button.
  3. Step 3: While holding down both the odometer's trip and reset buttons, turn the ignition switch to “on”

What is the first thing to check when the check engine light comes on?

Check your gas cap first. Many vehicles have a loose gas cap indicator that will be triggered before your check engine light comes on. If your gas cap is loose or the seal is not tight, the vapor leakage can cause your fuel system to trigger the check engine light.

Can a check engine light mean nothing?

Yes, a check engine light can come on due to a false alarm. This can happen because of temporary electrical glitches, sensor errors, or even software bugs in the car's computer system.

How long does it take for AutoZone to check engine light?

The test often takes less than a minute once the reader is plugged in. Find the closest store to you.

How do I find out why I have a check engine light?

Here are the top 5 reasons why your check engine light might be on and what to look for:
  1. Loose Gas Cap. This is the first item you should check. ...
  2. Failing Oxygen Sensor. ...
  3. Failing Catalytic Converter. ...
  4. Failing Mass Air Flow Sensor. ...
  5. Damaged Spark Plugs or Wires.

Who reads engine codes for free?

Stop by O'Reilly Auto Parts and we'll test your Check Engine light codes for free. We can even print out a list of common fixes for the codes, and help you find a repair shop if needed.

Can a check engine light be false?

Another reason the check engine light is illuminated could be that it's a false alarm. While that might sound like something to hope for, the truth is, if the light is on, something is wrong with your vehicle's systems.

Can low coolant cause a check engine light?

If your car's fluid levels, such as oil, transmission fluid, or coolant, are running low, it can cause your engine to function improperly. This can trigger your check engine light and potentially lead to more severe engine damage if not addressed promptly.

Will needing an oil change make check engine light come on?

In conclusion, while the check engine light can be a cause for concern, it can come on for something as simple as needing an oil change.

What is the most probable cause of a check engine light?

Sometimes, the sensor itself can fail or give faulty readings and may need to be replaced. The emissions/exhaust system is the most likely culprit for many check engine lights being illuminated. There could be an exhaust leak or a problem with the catalytic converter.

How much does it cost to fix a check engine light?

Diagnostic fees alone can range from $50 to $200, while repairs can cost anywhere from a few dollars for a loose gas cap to several thousand dollars for more complex problems. If you find yourself facing a check engine light, it's important not to ignore it.

Can I drive home if my check engine light is on?

If the light comes on and remains on, yet everything seems to be working like normal, you should be able to continue driving. But it is important to schedule an appointment to have the issue diagnosed and fixed. If the light comes on and it is blinking, this is an indication of something more serious.

Will AutoZone check engine codes?

We can help you get a reading yourself. Borrow an OBD reader to get a Check Engine Light reading with the AutoZone Free Fix Finder Service. It's a simple task that takes less than two minutes.

Why did my check engine light come on out of nowhere?

The “check engine” light is the onboard diagnostic system's way of telling you something's wrong. But that something could be one of many things, big or small. It could pop on because of something minor like a loose or faulty gas cap. It could also mean a major engine failure.

What code will a bad catalytic converter cause?

A common emissions code seen in the field, a P0420 trouble code indicates that the catalytic converter isn't functioning efficiently. To work at peak efficiency, the emissions or feed gases entering the catalytic converter need to be perfectly balanced and not excessively elevated.

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