The Ultimate Guide to Smog Checks in California: Costs, Rules, Locations & How to Pass

If you're like most Californians, you’ve probably typed “smog check near me” into your phone while racing a DMV deadline. Whether you're renewing your registration, selling a car, or just staying compliant, a smog check is something almost every driver has to deal with at some point.

In this detailed guide, we’ll break down everything you need to know: what a smog check is, how much it costs, how long it takes, how to pass—even with a check engine light—and how to find the best smog check near you.

What Is a Smog Check?

A smog check is a test that measures the level of pollutants (like hydrocarbons, carbon monoxide, and nitrogen oxides) coming from your car’s exhaust. These emissions can harm the environment and public health, so California requires them to be kept in check.

The purpose is to make sure your vehicle isn’t releasing more pollution than it should. Think of it as an environmental checkpoint that your car has to pass before the DMV will let it continue on the road legally.

Who Needs a Smog Check in California?

Almost every vehicle registered in California needs a smog check at some point. The exceptions are:

• Gasoline vehicles 8 years old or newer (exempt from biennial checks) • Electric vehicles • Diesel vehicles under 14,000 pounds and newer than model year 1998 • Hybrids only require OBD-based smog tests (no tailpipe emissions)

If your vehicle doesn’t fall into one of those exceptions, you'll likely need a smog check: • Every two years for ongoing registration • When selling or transferring ownership • When bringing a car into California from another state

What Is a STAR Smog Check?

Some vehicles are required to get tested at a STAR certified smog station, which is a higher-standard inspection facility monitored by the Bureau of Automotive Repair (BAR). If your DMV paperwork says "STAR required," don’t ignore it—you’ll need to find a STAR smog check near me.

These stations follow stricter protocols and are often used to test vehicles known for higher emissions or past smog check issues.

How Long Does a Smog Check Take?

A typical smog check takes about 20 to 30 minutes. If your vehicle is in good working condition and the station isn’t busy, it can be even faster.

However, older or specialty vehicles may take longer due to additional tailpipe tests or visual inspections.

Want to save time? Search for a smog check near me that offers appointments or check-in online.

How Much Is a Smog Check?

The smog check cost can vary based on your location, vehicle type, and whether it’s a STAR-required test. Here’s a rough breakdown: • Regular Smog Check: $40 – $60 • STAR Certified Smog Check: $60 – $90 • Diesel Smog Check: $70 – $100 • OBD-Only Smog Test (hybrids): $30 – $50

You might ask, “How much does a smog check cost in California?” Expect to pay slightly more in urban areas like Los Angeles, San Jose, or San Francisco.

Where Can I Get a Smog Check Near Me?

Looking for a smog check station nearby? You can find certified locations all across the state. Try searching for:

Or visit Smog Check Network to compare prices, availability, and station reviews in your area.

Can I Use a Groupon for Smog Check?

Yes! Many stations offer Groupon smog check deals or online coupons. Some promotions drop the price to as low as $9.99 (though additional fees may apply).

Just be sure the station accepts it and is STAR certified if required by your DMV.

What Do You Need for a Smog Check?

Here's what to bring: • Your car (obviously) • DMV renewal notice (optional, but helpful) • Valid ID (occasionally requested)

If you're wondering, “What do you need for a smog check?” — that’s it. The shop handles the rest.

What If I Have a Check Engine Light On?

A lot of people ask, “Can you pass smog with a check engine light?” Unfortunately, no.

In California, any illuminated warning light will automatically fail your vehicle—even if everything else looks great.

How to Pass a Smog Check (Even After Repairs)

If you're stressed about failing, here are tips on how to pass a smog check: • Warm up your engine with 15–20 minutes of highway driving before the test. • Fix any check engine light issues and drive your car at least 50–100 miles after repairs to reset the system. • Avoid testing immediately after disconnecting the battery. • Use quality fuel and change your oil if it’s due—old oil can cause higher hydrocarbon readings.

You might also ask, “How to pass smog with check engine light on?” Technically, you can’t. You'll need to clear the fault, confirm the monitor readiness, and then test.

How Often Is a Smog Check Required?

Wondering, “How often is a smog check required in California?” Here’s a simple breakdown: • Every 2 years after your vehicle is over 8 years old • Upon ownership transfer • When bringing in a car from another state

Your registration renewal notice will tell you if you need one. If it says STAR required, start by searching for a STAR smog check near me.

How Long Is a Smog Check Good For?

Once you pass a smog check, the results are valid for 90 days. That’s the window in which you need to complete your registration.

After 90 days, you may be required to test again. The results are sent electronically to the DMV, so no paperwork is needed on your end.

DMV Smog Check Process

The DMV smog check process is simple: 1. Get tested at a certified smog station. 2. If you pass, the results are automatically uploaded to the DMV. 3. If you fail, repair the issue and retest.

The DMV won’t let you renew your tags until a valid smog check is on file—unless you qualify for a hardship extension or waiver.

What Happens If You Fail?

If you fail, don’t panic. You’ll receive a diagnostic report telling you why. Common issues include: • Faulty oxygen sensor • Leaking EVAP system • Dirty air filter • Engine misfire • Malfunctioning catalytic converter

Once repaired, you can go back for a retest, often at a discounted rate.

Conclusion: Smog Checks Don’t Have to Be Stressful

Sure, no one loves emissions testing. But when you know what to expect—and where to go—it becomes just another step in being a responsible car owner in California.

Here's a quick recap: • A smog check is required every 2 years for most vehicles. • Some require a STAR smog check, so check your DMV notice. • Smog check cost ranges from $30–$90 depending on the test type. • Look for deals via Groupon smog check or local coupons. • You cannot pass with a check engine light on—get it fixed first. • Most tests take 20–30 minutes and are valid for 90 days.