What is the Most Common Reason for a Check Engine Light?

A loose gas cap is the most common reason there’s a check engine light on your dashboard. When the cap is loose or damaged (usually cracked), the fuel system loses pressure, and the warning light turns on. While this is the most common reason, there are some other reasons you should consider before bringing your vehicle to Selden’s best-rated auto shop for a check engine light diagnostic test.

Why is Your Check Engine Light On? It’s Likely One of These 5 Problems

While the loose or faulty gas cap leads on pure percentage numbers (around 10% of all cases), there are other common issues that cause the check engine light to turn on.

1. Loose or Faulty Gas Cap: The aforementioned loose or missing gas cap is something you can check at home. Open the door covering the gas cap, ensure the cap is tight, and check the dashboard light again. If it has turned off, then the cap was simply loose. If the light’s still on, you likely need a replacement cap to restore pressure in the fuel system.
2. Faulty Oxygen Sensor: Another common symptom leading to Selden check engine light repair is a faulty oxygen sensor. This critical sensor measures oxygen in the exhaust gases to track efficiency. A failing oxygen sensor reduces fuel economy and could lead to expensive problems like a faulty catalytic converter.
3. Catalytic Converter Problems: The catalytic converter can cause a check engine light when the interior ceramic honeycomb inside it melts. This can happen when fuel enters the exhaust and ignites inside the catalytic converter. Physical impacts and contamination from leaking oil can cause a catalytic converter to go bad. Often, the light is a sensor issue, but it could also indicate a failed catalytic converter.
4. Mass Airflow Sensor Issues: The mass airflow sensor measures the air entering the engine, helping to ensure proper combustion. A malfunctioning airflow sensor will turn the check engine light on, and you might notice problems like stalling or sluggish acceleration.
5. Ignition System Problems: Worn-out spark plugs and failing coils can cause misfires and an illuminated check engine light. You will likely feel this issue at the same time as seeing the light. Ignition problems can cause stuttering when accelerating and random engine cut-outs.
   

Never Ignore a Check Engine Light

Ignoring the check engine light risks serious mechanical and electrical problems. Modern cars have two check engine light states:

• A solid check engine light is a warning that you need to get your car to a mechanic for a check engine light diagnostic service.
• A flashing check engine light is a severe warning. Stop the car somewhere safe and arrange a tow for vehicle diagnostics. This usually indicates misfires or severe electromechanical issues.

The Best Shop for Check Engine Light Diagnostics Near You in Selden, New York

Dee Pat’s Awsomotive uses advanced diagnostic tools to interface with your car’s computer and check all of the recent logs and warning codes. Our OBDII scanners can reveal hidden issues to prevent expensive repairs later. We will quickly identify the cause of a check engine light, physically confirm the problem, and recommend a cost-efficient repair.



We are located in the heart of Selden, making our check engine light diagnostic service convenient if you’re around the corner or in nearby areas like Coram and Centereach. Talk to our team at (631) 538-4441 to book your appointment for vehicle diagnostics today.