What a Five Star Smog Check Means

A Five Star Smog Check is California's enhanced vehicle emissions testing program, designed to catch vehicles that pollute more than standard models. It is not a separate test you request — it is an additional inspection that the Bureau of Automotive Repair (BAR) assigns to certain vehicles based on their age, make, model, and emission history. If your vehicle is flagged for a Five Star test, you must pass it to renew your registration.

The Five Star program targets vehicles that have failed previous smog checks, have been flagged for high emissions, or fall into model years and makes known for emission problems. The test itself is more rigorous than a standard smog check: it includes a dynamometer test (where your vehicle runs on a rolling machine while emissions are measured), an on-board diagnostic (OBD) scan, and a visual inspection. A standard smog check uses only the OBD scan and visual inspection for most vehicles.

You cannot opt out of a Five Star test if you are assigned one. The test must be performed at a BAR-certified smog station, and the results are reported directly to the California Department of Motor Vehicles (DMV). If you pass, your registration can proceed. If you fail, you have options for repair and retesting.

Key Takeaways

  • Five Star tests are assigned by the state to specific vehicles based on age, model, and past emission failures — you do not choose to take one.
  • The test includes a dynamometer run, OBD scan, and visual inspection, making it more thorough than a standard smog check.
  • Only BAR-certified smog stations can perform Five Star tests, and results go directly to the DMV.
  • If you fail, you can repair your vehicle and retest at the same station, and the state may cover some repair costs through the Consumer information Program.
  • Five Star tests cost more than standard smog checks — typically between $100 and $200 depending on your vehicle and location.

Who Gets Assigned a Five Star Test

The state assigns Five Star tests based on specific criteria. Vehicles that have failed a smog check in the past two years are the most common candidates. Vehicles from model years known to have emission control problems are also flagged, as are vehicles with a history of high emissions readings. You can check whether your vehicle is flagged by visiting the BAR website or calling your local smog station before you schedule a test.

Older vehicles — typically those 1975 and newer — are more likely to be assigned Five Star tests than newer models, though newer vehicles with emission issues can also be flagged. Diesel vehicles, hybrids, and certain makes and models with known emission problems are flagged more frequently. The state updates its flagging criteria annually based on emission data.

If you are unsure whether your vehicle will require a Five Star test, contact a BAR-certified smog station in your area with your vehicle identification number (VIN) and current registration. They can tell you what test type your vehicle needs before you arrive.

How the Five Star Test Works

The Five Star test has three main components. First, the smog technician performs a visual inspection of your vehicle's emission control systems — the catalytic converter, air filter, fuel cap, and other visible parts. Second, they connect a diagnostic scanner to your vehicle's OBD port to read any stored or pending emission-related fault codes. Third, they place your vehicle on a dynamometer and run it through a standardized driving cycle while measuring tailpipe emissions for nitrogen oxides (NOx), particulate matter, and other pollutants.

The dynamometer portion is what distinguishes Five Star from a standard test. Your vehicle is driven on the rolling machine for several minutes, simulating highway and city driving conditions. The machine measures how much pollution your vehicle produces under load. This catches vehicles that pass an OBD scan but still emit excessive pollutants when actually driven.

The entire test typically takes 30 to 45 minutes. You will receive a printed report showing whether you passed or failed, along with any fault codes or emission readings that exceeded state limits. If you pass, the station submits your results to the DMV electronically, and you can proceed with registration renewal.

What Happens If You Fail a Five Star Test

If your vehicle fails a Five Star test, you have two main paths forward: repair the vehicle and retest, or pursue a waiver. Most vehicles that fail can be repaired. Common failure reasons include a faulty oxygen sensor, a malfunctioning catalytic converter, a vacuum leak, or a failed emission control component. A smog technician can often diagnose the specific problem and recommend repairs.

You are not required to repair at the same station where you tested, but that station can provide a diagnostic report that helps any mechanic understand what needs fixing. After repairs, you must retest at a BAR-certified station. If you pass the retest, your registration can proceed. If you fail again, you can repair and retest once more before the state may require a waiver process.

California's Consumer information Program (CAP) may cover some repair costs if your vehicle fails and you meet income limits. CAP covers up to $500 of repairs for vehicles that fail smog checks, and in some cases up to $1,000. You must be the registered owner, have a household income at or below 225% of the federal poverty line, and have owned the vehicle for at least two years. Contact your local air quality management district to learn whether CAP is available in your area and how the process works.

Cost and Timing for Five Star Tests

Five Star tests cost more than standard smog checks because of the dynamometer equipment and additional testing time required. Prices vary by location and smog station, but typically range from $100 to $200. Some stations charge a flat rate; others charge by the test type. Call ahead to confirm the price at your chosen station.

The test itself takes 30 to 45 minutes. However, if the station is busy, you may wait longer. It is wise to schedule an appointment rather than walk in, especially at busy times of year (late summer and early fall, when registration renewals peak). If you fail and need repairs, add time for the repair shop to diagnose and fix the problem — this can range from a few hours to several days depending on the issue and shop availability.

Your registration renewal important date does not change because you are taking a Five Star test. If your registration expires on a specific date, you must pass the test and submit results to the DMV before that date. Plan ahead if you suspect your vehicle may fail, so you have time to repair and retest.

Finding a BAR-Certified Smog Station

Not all smog stations are certified to perform Five Star tests. The Bureau of Automotive Repair maintains a searchable list of certified stations on its website at bar.ca.gov. You can search by county or ZIP code to find stations near you. When you call or visit, confirm that the station is certified for Five Star testing and ask about their current wait times and pricing.

Some stations specialize in Five Star tests and may have more experience with the dynamometer equipment. Others perform them less frequently. If your vehicle has a complex emission problem, a station with more Five Star experience may be able to diagnose the issue more quickly. Read online reviews if available, and do not hesitate to call multiple stations to compare prices and availability.

Bring your vehicle registration and a valid photo ID when you go for your test. Have your VIN ready so the technician can verify which test type your vehicle requires. If you have had recent repairs done to your emission control system, bring documentation of that work — it may help the technician understand your vehicle's history.

Frequently Asked Questions

Can I drive my vehicle if it fails a Five Star test?

Yes, you can continue to drive it while you arrange repairs and retesting. However, you cannot renew your registration until you pass. If your registration expires before you pass the test, you are driving with an expired registration, which is illegal. Plan your repairs and retest before your registration important date.

What if I repair my vehicle and it still fails the Five Star test?

You can retest after additional repairs. If you fail twice, you may be able to request a waiver from your local air quality management district, though waivers are not may provide. The district will review your repair attempts and may grant a waiver if you have made good-faith efforts to fix the problem. Contact your district to learn their waiver process.

Does the Consumer information Program cover all repair costs?

No. CAP covers up to $500 of repairs for most vehicles, or up to $1,000 in some districts. You must meet income limits (at or below 225% of federal poverty line) and own the vehicle for at least two years. Not all repairs are covered — only those directly related to the emission control system. Contact your local air quality management district to confirm what is covered in your area.

How long does a Five Star test result stay on my vehicle's record?

A passing result is submitted to the DMV and clears your vehicle for registration renewal. A failing result does not expire, but it only matters if you fail to repair and retest before your next registration renewal. Once you pass a retest, the previous failure is superseded by the passing result.

Can I take my Five Star test in a different county than where I live?

Yes. You can take your test at any BAR-certified station in California. The results are reported to the DMV under your vehicle's VIN and registration, regardless of where the test was performed. Some people travel to a different county if they believe a particular station has better equipment or informed, though this is not necessary for most vehicles.