We often panic when the check engine light appears on the dashboard. Relax—the light comes on as a warning that something might not be quite right with your vehicle. Let a skilled mechanic take a look, assess the situation and confirm—or dismiss—any concerns. Familiarize yourself with the most common sources of a check engine light, and you’ll be better prepared to discuss the repair with your mechanic and understand what your car needs.
Misfire - A misfire in your engine can be traced back to any number of reasons, ranging from a problem with the spark plugs or plug wires to the distributor cap coils of the fuel injectors.
Emissions - Your check engine light can also come on to indicate a problem with your evaporative emissions system, which prohibits harmful vapors from escaping from your vehicle and into the atmosphere. The failure can arise from a variety of reasons, including a loose or defective gas cap, a broken gas cap seal or a leak in a plastic tube that runs between the engine compartment and the fuel tank.
Failed oxygen sensor - Your car’s oxygen sensor (O2 sensor) measures and regulates the amount of unburned oxygen in your vehicle’s exhaust system. Faulty sensors can damage your car’s spark plugs and catalytic converter, as well as cause your car to burn more fuel than necessary.
Catalytic converter - Your catalytic converter changes harmful carbon monoxide into carbon dioxide. Faulty oxygen sensors or damaged spark plugs or wires can damage a catalytic converter.
Mass airflow system - Your mass airflow system (MAS) measures the amount of air that enters the engine of your car and determines how much fuel your engine requires to run efficiently. A damaged mass airflow system can cause reduce your vehicle’s performance and result in low fuel economy, as well as damage or ruin your spark plugs.