Check Engine Light Came On but Car is Running Fine
What to Do
The check engine light is a warning light that can be illuminated by a variety of issues, some of which are more serious than others. If the check engine light comes on but your car is running fine, it’s important to take the following steps:
1. Check for loose or damaged gas caps
A loose or damaged gas cap can cause the check engine light to come on. This is because the gas cap helps to seal the fuel system and prevent vapors from escaping. If the gas cap is loose or damaged, vapors can escape and trigger the check engine light.
To check for a loose or damaged gas cap, simply open the gas cap and inspect it. If the gas cap is loose, tighten it until it clicks. If the gas cap is damaged, replace it with a new one.
2. Check for vacuum leaks
A vacuum leak can also cause the check engine light to come on. A vacuum leak occurs when air enters the engine through a hole or crack in the intake manifold or other vacuum lines. This can cause the engine to run lean, which can lead to a variety of problems, including decreased fuel economy, rough idling, and engine stalling.
To check for a vacuum leak, use a vacuum gauge to measure the vacuum in the intake manifold. If the vacuum is below the manufacturer’s specifications, there may be a vacuum leak. You can also use a smoke machine to locate a vacuum leak. A smoke machine will produce smoke that will be drawn into the engine through any vacuum leaks.
3. Check for spark plugs and wires
Spark plugs and wires can also cause the check engine light to come on. Spark plugs are responsible for igniting the air-fuel mixture in the engine’s cylinders. If the spark plugs are worn out or damaged, they can cause the engine to misfire. This can lead to a decrease in fuel economy, rough idling, and engine stalling.
Spark plug wires are responsible for carrying the electrical current from the ignition coil to the spark plugs. If the spark plug wires are damaged, they can cause the spark plugs to misfire. This can lead to the same problems as worn out or damaged spark plugs.
To check for worn out or damaged spark plugs and wires, simply remove the spark plugs and inspect them. If the spark plugs are worn out, they will be black and have a rounded edge. If the spark plug wires are damaged, they will be cracked or frayed.
4. Check for oxygen sensors
Oxygen sensors are responsible for measuring the amount of oxygen in the exhaust gas. This information is used by the engine’s computer to adjust the air-fuel mixture. If the oxygen sensors are faulty, they can cause the engine to run rich or lean. This can lead to a variety of problems, including decreased fuel economy, rough idling, and engine stalling.
To check for faulty oxygen sensors, use a scan tool to read the oxygen sensor data. If the oxygen sensor data is not within the manufacturer’s specifications, the oxygen sensors may be faulty.
5. Check for catalytic converter
The catalytic converter is responsible for reducing the emissions from the engine. If the catalytic converter is damaged or clogged, it can cause the check engine light to come on. This can lead to decreased fuel economy and increased emissions.
To check for a damaged or clogged catalytic converter, use a scan tool to read the oxygen sensor data. If the oxygen sensor data is not within the manufacturer’s specifications, the catalytic converter may be damaged or clogged.
If the check engine light is still on
If you have checked all of the above items and the check engine light is still on, it is important to take your car to a qualified mechanic for further diagnosis. The mechanic will be able to use a scan tool to read the trouble codes from the engine’s computer. This information will help the mechanic to identify the cause of the check engine light and recommend the appropriate repairs.
Conclusion
The check engine light is a warning light that should not be ignored. If the check engine light comes on, it is important to take the steps outlined above to diagnose the cause of the problem. By addressing the problem early on, you can help to prevent more serious damage to your car.
