Does a Check Engine Light Affect Smog Check?: 1 Minute to Understand the Impact of Engine Lights on Emissions Testing

If your car's check engine light is on, you're probably wondering if it can still pass a smog check. The short answer is: it depends. A lit check engine light could be a sign of an underlying issue that may affect emissions. In many states, vehicles with a check engine light illuminated will automatically fail the smog test.

It's essential to address the reason behind the check engine light before bringing your vehicle in for inspection. In some cases, it could be a minor issue, like a loose gas cap, but other times, it might indicate more serious problems that need immediate attention.

What to Do Before the Smog Check

1. Diagnose the Problem: Use an OBD-II scanner to check for diagnostic trouble codes (DTCs). This will help you identify the specific issue causing the check engine light to illuminate.

2. Repair Any Issues: Once you know what's wrong, take your car to a qualified mechanic. They can perform the necessary repairs or adjustments to reset the check engine light.

3. Clear Codes: After repairs are made, make sure to clear any codes using a scanner. You will need to drive your car for a few days to ensure the vehicle is ready for the smog test.

What Happens During the Smog Check?

During the smog check, the technician will test your vehicle's emissions and check for any visible leaks. If your check engine light is on, they may not proceed with the test and may suggest you fix the issue first.

Conclusion

In summary, having a check engine light on can significantly impact your vehicle's ability to pass a smog check. It's always best to resolve any issues indicated by the check engine light before scheduling your smog inspection.

FAQ

Q: Can I still drive my car if the check engine light is on?A: While it may be possible to drive your car, you should address the issue quickly to avoid further damage or failing an emissions test.

Q: What are common reasons for a check engine light to be on?A: Common reasons include a loose gas cap, faulty oxygen sensors, or issues with the catalytic converter.