Seeing the check engine light come on in your Subaru can stir up a mix of worry and confusion. For many drivers, it’s a signal that something could be seriously wrong, but it’s not always easy to tell what’s going on under the hood. Subaru vehicles, known for their reliability and all-wheel-drive performance, are not immune to occasional engine issues.
Understanding what triggers this warning can help you take the right steps and avoid further damage to your engine or emissions system.
What the Check Engine Light Actually Means
The check engine light is part of your Subaru’s onboard diagnostic system (OBD-II). When it lights up, the computer has detected something out of the ordinary. This might be a minor issue, such as a loose gas cap, or something more serious, like a misfiring cylinder or a failing catalytic converter.
Some check engine lights come on and stay solid. This usually indicates a non-urgent issue that still needs attention soon. A flashing check engine light, however, is a more serious sign. It often indicates a misfire that can damage the catalytic converter if not addressed promptly.
Common Reasons for the Light in Subaru Models
There are a few common culprits behind the check engine light in Subarus. One of the most frequent is a faulty oxygen sensor. This component monitors your car’s emissions and helps the engine adjust the air-fuel mixture. When it fails, it can cause reduced fuel efficiency and increased emissions.
Another common reason is a failing mass airflow sensor (MAF), which measures the amount of air entering the engine. A problem here can throw off the engine’s performance and cause stalling or hesitation.
Subaru drivers also frequently encounter issues with the ignition coil or spark plugs. A misfiring spark plug can lead to poor fuel economy and rough idling. Replacing plugs and coils is a relatively routine repair, but it shouldn’t be delayed once a misfire is detected.
Subarus with older or worn-out gas caps may also trigger the check engine light. If the cap isn’t sealing properly, it can cause a drop in fuel system pressure and result in an EVAP (evaporative emissions) code. This is one of the simplest fixes, and sometimes just tightening the gas cap will turn the light off.
Engine Misfires and Their Consequences
One issue Subaru owners should not ignore is an engine misfire. In many models, a misfire can lead to raw fuel entering the exhaust system, damaging the catalytic converter. These converters are expensive to replace and are also crucial for maintaining clean emissions.
Misfires can occur due to bad spark plugs, ignition coils, dirty fuel injectors, or even a failing head gasket. Subarus are particularly known for head gasket issues in earlier models, so if your vehicle is experiencing overheating or white smoke along with a check engine light, this could be the cause.
Why You Shouldn’t Ignore the Light
Some drivers are tempted to ignore the check engine light, especially if the vehicle seems to run fine. However, many problems that cause this warning can worsen over time and lead to more expensive repairs. Even something minor can trigger a chain reaction of issues.
An illuminated light also usually means your car will fail a smog or emissions test. This can prevent you from renewing your registration until the problem is resolved.
What to Expect During a Diagnostic Check
When you bring your Subaru in for service, the first step is a diagnostic scan. Technicians use a code reader to access the trouble codes stored in the vehicle’s computer. These codes provide a starting point for diagnosis. For example, a P0302 code tells the mechanic there’s a misfire in cylinder 2, while a P0420 might indicate an issue with the catalytic converter.
Once the technician has the code, they’ll perform a series of tests to confirm the root cause. It’s not enough to just clear the code because any underlying problem must be addressed to prevent the light from coming back.
Keep Your Subaru Healthy with Help from The Model Garage in Berkeley, CA
If your check engine light has turned on, don’t wait to find out why. The Model Garage in Berkeley, CA, specializes in Subaru service and repairs. Our technicians know these cars inside and out and can quickly pinpoint the cause of any warning light or drivability concern.
Bring your vehicle in today for a thorough diagnostic check, and let us help you get back on the road with confidence.