Check Engine Light 

Indicates the engine computer has set a Diagnostic Trouble Code (DTC). Usually requires diagnosis with a professional scan tool

Top 5 Reasons for a Check Engine Light:

1. Your Oxegen Sensor (O2 Sensor): Needs to be replaced

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

What happens if you dont 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

2. 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

3. 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

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


Your mass airflow sensormeasures 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.

5. Your vehicle needs new Spark Plugs or Wires.


Your spark plugs ignite the air/fuel mixture in the combustion chamber of your vehicle. The spark plug wiresdeliver 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

Top 5 Reasons for a check engine light


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