Is Your Car's Check Engine Light Constantly On?

Many fault codes can tell the computer system to show the "check engine" light. For example, the fault code P0420 means that the Catalyst System Efficiency is below the acceptable threshold. But, in short, the check engine light can indicate plenty of things, and the auto shop technician's testing procedures tell the root issue precisely. Additionally, you might notice the car's weaker performance, burning-like smells, and poor fuel economy. But note that your vehicle emitting a warning code doesn't mean that you need to buy new parts and make drastic changes; rely on a mechanic to make proper testing and avoid over expenses.

A technician can clear the "check engine" light using specific tools. However, this would only mask the problem. It's essential to understand that any engine computer alert is troublesome and can develop into something worse, costing safety and money. In addition, the engine computer has a feature that stores information concerning the vehicle's overall condition when the problem first popped up. This feature helps technicians reproduce the issue when testing by mimicking the operating condition from before, making their jobs easier and more precise.

For example, the "check engine" light pops up, and the engine computer stores that a misfire occurred. In this case, the driver might even notice symptoms like poor fuel economy and performance loss. Then, the misfire information that the engine computer stored will be available for the technician during special testing and evaluation, telling which driving conditions a misfire occurred, which caused the "check engine" light. Finally, the technician will use this stored information to know what kind of tests to perform.

We recommend you not to. The issue with driving with the "check engine" light on is that it is your vehicle's only engine warning light. So, if any other problem adds up to the car's engine or electrical system, you won't know because there won't be an extra warning; the light is already on.

In this case, you may lead your vehicle to show more noticeable symptoms. For example, if a variable valve timing defect occurs, symptoms may include a rattling and ticking noise, power loss, fuel mileage drop, and oil leaks. You'll need to share these or other clues with your shop.

A loose oil or gas cap can alert the computer system, which then notifies the driver with the "check engine" light. Fortunately, some modern vehicles even have a specific "check gas cap" alert. A loose gas cap has this impact because it allows evaporative leaks.

If it's not a loose gas cap, the problem is elsewhere, and it's possible that your car shows these symptoms: no performance drop, raw fuel smell, and "check engine" light. In this case, you'll need additional testing to get your car past an emission test to renew its registration.

If a catalytic converter isn't working correctly, the "check engine" light pops on the dashboard. Still, note that this does not mean the catalytic converter is broken; many parts working alongside it can sabotage and impact the converter's workflow. For example, engine misfires, ignition fuel, intake problems, and a failed mass air flow sensor can cause this type of issue. Common symptoms of this problem are poor fuel mileage, engine underperformance, surging, and hesitation.