Will You Pass A Smog Check If Your Check Engine Light Is On?

Check Engine Light

No, it is likely your vehicle will not pass a smog check if your check engine light is on, but let's look at this further. Dhillon Motorsports, formerly known as Smog Man San Jose are experts who can spare you grief if you'll bring your vehicle into our shop the minute the check engine light comes on. This warning light doesn't always mean an expensive repair bill. Rather, it could be something simple, such as a loose gas cap that's triggering the onboard computer to turn on the check engine light.

Your Check Engine Light and Emissions

Generally, the check engine light illuminates when your vehicle is experiencing an emissions problem, and this is the primary reason why it won't pass a smog check with the light on. Whether there is a legitimate issue or not, your onboard computer has detected a fault, and it will return that fault until it is fixed or the computer is reset. This is why we say it is likely your vehicle won't pass the smog test. If there's nothing wrong and the fault was returned in error, all we need to do is reset the computer and then it should pass the test.

This Being Said…

This is rare, however, which is why we encourage every driver to take a check engine light warning seriously. In most cases, the light will only shine when there is something wrong with the engine, so you should never ignore the dashboard signal. Some of the things that could be going wrong under the hood when your check engine light comes on are an oxygen sensor failure, catalytic converter failure, or spark plug and plug wire failure. Serious stuff!


All of these things contribute to the emissions your car, truck, or SUV releases into the environment, which is why when the check engine light turns on your smog test results are guaranteed to be “fail.” California is strict on emissions, and your vehicle won't pass the smog test if there is an issue with the exhaust system. To prevent further hassle, have your vehicle smog checked at a place that also offers repairs. This means the mechanics can diagnose why your vehicle failed the smog test, repair the issue, and then conduct a smog retest.

Located in beautiful San Jose, CA, Dhillon Motorsports, formerly known as Smog Man San Jose knows check engine warning lights and the codes they return. Should yours come on, we can tell you why and fix the issue. Then, we can get your vehicle to pass its smog check. Call us today at 408-999-0699.


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