Learn the Top 5 Reasons
Why your check engine light may be on


The AutoZone Fix Finder

An easy-to-use tool to troubleshoot why your Check Engine Light is on, Fix Finder utilizes an extensive database of repair solutions from ASE certified mechanics to help you find the most likely fix.

How does AutoZone Fix Finder work?

  • Fix Finder reads diagnostic trouble codes from your vehicle’s onboard diagnostic system, and pulls your vehicle information and mileage.
  • This data is analyzed to give you vehicle-specific fix solutions that have been verified from the records of over 5.5 million ASE-Certified technicians.
  • AutoZone gives you a FREE, easy-to-read MYZONE HEALTH REPORT, which includes relevant codes, and details the action that needs to be taken.

Visit your local AutoZone store and let us help you find out if the problem is simple or serious

Your Check Engine Light may be indicating a simple problem that’s easy to fix—such as a loose gas cap that needs to be replaced. It could also be a warning of a serious problem that could damage your engine components.

Your Check Engine Light blinks or glows depending on what’s wrong with your vehicle. A flashing Check Engine Light indicates that your vehicle’s engine is in serious trouble, whereas a steadily lit one means less urgent service is needed. Regardless, it’s easy to find out what the issue is, and taking care of it quickly can save you money, and prevent further damage down to the road.

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Your Oxygen (O2) Sensor needs to be replaced

Your oxygen sensor measures the amount of unburned oxygen in your vehicle's exhaust system.

What happens if I don’t replace it?

  • Your engine will burn more fuel than needed
  • You will lose fuel economy, and get less miles per gallon
  • Faulty sensor(s) can cause damage to your spark plugs and catalytic converter

Gas cap is loose, damaged or missing

Your gas cap seals the fuel system and helps maintain pressure within the fuel tank. It also prevents gasoline fumes (hydrocarbons) from being released into the atmosphere while you aren't driving your car.

What happens if I don’t replace it?

  • You can lose fuel through evaporation
  • You may take more trips to the gas pump

You have a bad catalytic converter

Your catalytic converter helps protect our environment by converting harmful carbon monoxide into carbon dioxide. Damage usually occurs due to neglected maintenance (like the parts in reasons # 1, 4, and 5).

What happens if I don’t replace it?

  • Your vehicle will not pass an emissions test
  • You will experience reduced performance and fuel economy
  • Your car may run at a higher temperature

It's time to replace your Mass Airflow Sensor (MAF)

Your mass airflow sensor measures the amount of air entering the engine to determine how much fuel is needed to run your engine efficiently.

What happens if I don’t replace it?

  • Faulty sensors can cause damage to spark plugs, O2 sensors or catalytic converter
  • You will experience reduced performance and fuel economy

Your vehicle needs new Spark Plugs or Plug Wires

Your spark plugs ignite the air/fuel mixture in the combustion chamber of your vehicle. The spark plug wires deliver the spark from the ignition coil to the spark plugs.

What happens if I don’t replace it?

  • You will experience poor performance (reduced power, engine missing) and reduced fuel economy
  • Worn plugs and plug wires can cause clogged catalytic converter or damage to ignition coils and O2 sensors
These are the most common reasons, but there are others too. Finding out why your Check Engine Light is on may help you save gas and avoid more problems down the road. Get in the Zone.

Doing a Simple Tune-Up

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Other Dash Lights

See what some of the most common other dashboard lights indicate and visit your local store to troubleshoot.

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