Free Check Engine Light Diagnostics: 5 Auto Stores Near You!

Issues with the oxygen sensor

Oxygen sensors are a common cause of check engine lights.

Oxygen sensors are used to make sure your vehicle is burning the correct amount of fuel and running at peak performance. And, it also works with the catalytic convertor to keep emissions in check. Over time, the O2 sensor can get covered in oil ash, which reduces its ability to monitor the fuel and oxygen mix in the engine. It costs around $200 to fix.

Loose, faulty, or damaged gas cap

Something as simple as a loose, faulty, or damaged gas cap can cause the check engine light to illuminate.

If the gas cap is loose or damaged, it can disrupt your vehicle’s emissions systems, as fuel vapors may leak out of the gas tank, leading to a decrease in vehicle efficiency. You’ll need to tighten up a loose gas cap or replace a damaged one. The price of replacing it varies from $5 to $30.

By finding out and fixing the issue, you can save money on gas in the long run.

Issues with the catalytic converter

Catalytic converters reduce emissions of your vehicle by converting carbon monoxide and other dangerous gases into harmless compounds.

Usually, catalytic convertors last for a car’s lifetime or more than 300,000 kilometers. However, they can have issues. Unfortunately, this can be an expensive issue, costing around $2,000 to fix.

Problem with the mass airflow sensor

The mass airflow sensor helps your car’s computer to inject the right amount of fuel into the engine to increase its performance and efficiency.

It’s important to regularly service your car’s air filter, so you don’t risk damage to the vehicle’s mass airflow sensor. If you don’t replace the air filter, the air-flow sensor can malfunction, and provide incorrect information. This can lead to issues like car stalling, increased emissions, and poor gas mileage. That’s why you need to replace your car’s air filter at least once a year.

If there’s a problem with the mass airflow sensor, fixing it can be on the more expansive side. It costs from $200 to $375, on average, to fix.

Faulty spark plugs

Spark plugs usually last between 75,000 and 200,000 kilometers.

If there’s an issue with a spark plug, this can cause the engine warning light to turn on. They’re pretty cheap and easy to replace.

You can purchase spark plugs for about $10 to $20 apiece. If you take it to a shop to have them replaced, it can cost you a little more money.

What to Do When the Check Engine Light Comes On

When your check engine light comes on, it’s important to get it checked right away. It could signal a complicated issue, like a problem with the catalytic convertor or just something simple, like a faulty gas cap. But, you won’t know what the issue with your vehicle is until you have it checked.

It’s important not to panic. Sure, the engine light coming on doesn’t seem like a good thing, but it could be nothing at all or one of the simple issues I mentioned above.

Don’t go trying to replace parts without first diagnosing your issue. This is a waste of time and money. Instead, have your engine light checked. You can often do it for free.

Where to Get Free Check Engine Light Diagnostics

Here’s where you can get a free check engine light test.

1. Advance Auto Parts

Advance Auto Parts operates 4,966 stores. You can visit your local store to get free engine code scanning on most OBD-II vehicles. Advance Auto Parts says it cannot guarantee the problem can be resolved during the visit, but that it’s happy to refer you to one of its local professional technicians if a more comprehensive diagnosis is needed.

2. AutoZone

Get a free engine light check at AutoZone with the free AutoZone Fix Finder Service. AutoZone has more than 5,700 locations in the United States, and all of them offer the Free Fix Finder Service during business hours.

AutoZone calls its Fix Finder Service, “The most complete, free warning light report backed by the most robust database of technician solutions.”

When you get the engine light, visit your local AutoZone, and Fix Finder will read the information from Check Engine, ABS, and maintenance lights. The test often takes less than a minute once the reader is plugged in, so it’s a pretty quick process. Then, you’ll get an easy-to-understand report that’s informed by millions of technician-verified fixes. Handily enough, you get a printed and digital copy of the report.

The report details recommended solutions and suggests parts needed for repair. Staff members can help you to find the right part, and also recommend a local technician if you require additional help with the fix.

3. O’Reilly Auto Parts

O’Reilly Auto Parts offers a number of free services, such as:

• Free check engine light service
• Free battery testing
• Free wiper blade installation
• Fluid and battery recycling
• Loaner tool program

Head to your local O’Reilly Auto Parts store and it will scan your codes for you and provide a list of possible fixes. It says that some codes may call for further diagnosis, and when that occurs, they will be happy to refer you to a professional technician.

It will run your codes through a comprehensive database of more than 26 million verified fixes, which is good. And, it provides you with a free printout of verified fixes from a team of ASE Certified Technicians.

4. Napa Auto Parts

There are 6,000 Napa Auto Parts stores. And the store offers free engine light checks at some locations. Make sure you call ahead to see if this service is offered at your local Napa Auto Parts store.

5. Pep Boy Auto Parts

Pep Boy Auto Parts is another place where you can have your engine light checked for free.

It has more than 1,000 locations in the United States and Puerto Rico, and 9,000 service bays. Visit your local store for its Free Engine Light Code Pull Service Package.

Other Ways to Get a Free Car Diagnostic Check

There are a few other ways that you can have your engine light checked for free.

Check the codes yourself

You can check your PID fault codes yourself, but you will need to purchase an OBD-II scan tool, and then look the codes up online.

Amazon is a good place to buy this tool because it offers them at pretty low prices. This Universal OBD2 Scanner Car Code Reader, this Wireless Bluetooth OBD2 Scanner & Fault Code Reader and this WiFi Car Code Reader Check Engine Light Diagnostic Scan Tool are only around $20 each.

Once you get the PID code from the device you use, you can then research it online to see what the issue with your vehicle could be.

Visit a local mechanic

You may be able to get your light checked free of charge by visiting a local mechanic. You’ll have more chance of this if you already have a local mechanic that you visit for your usual car needs. Often, a mechanic will be able to provide you with more detailed information than you’d be able to get on your own. And, they’ll be able to tell you what’s going on with your vehicle.

If you have a mechanic you’ve used when your car has needed repairs or maintenance, get in touch and ask if they offer a free check engine light service.

Of course, if the problem diagnosis takes longer than expected, don’t expect it to be free, since mechanics do have to charge for their time.

This can be a good option if you have a mechanic that you trust because they can help you a lot with getting your car back to running properly.

Closing Thoughts

I would recommend getting a free scan at your local auto parts store, like AutoZone or Pep Boy Auto Parts. This can give you an insight into what the issue is with your vehicle, and what needs to be done to fix it.

Of course, there are other options like buying your own OBD-II scanner and checking the light yourself or taking the car to your regular mechanic.

Whatever option you choose, make sure you have your car engine light checked as soon as it comes on. And, don’t worry too much, as many times it’s a minor issue that causes the light to appear.

Give these places that offer free check engine light diagnostics a try.