California Smog Check
About 90,500 people search for a smog check near them every month. This guide covers when it’s required, what’s exempt, how much it costs, and how to find a station.
TL;DR
- California’s Smog Check Program is administered by the Bureau of Automotive Repair (BAR); the DMV enforces it through vehicle registration.
- A smog check is triggered by three things: biennial renewal, change of ownership, or first-time registration of an out-of-state vehicle.
- Exempt: electric vehicles, motorcycles, gasoline vehicles from 1975 and older, diesels from 1997 and older — plus gasoline/hybrid cars less than 8 model years old at renewal.
- No appointment needed — most stations take walk-ins, and no paperwork is required (the tech uses your VIN and plate).
- The $8.25 state certificate fee is charged only if your vehicle passes.
Do you need a smog check?
Answer 3 quick questions and get a straight answer — with the reason, not just a yes or no.
Question 1 of 2
When a smog check is required in California
A smog check is only required in one of these three situations. If none of them applies to you right now, you don’t need one.
Biennial registration renewal
Most vehicles need a smog check every 2 years when renewing registration, in Enhanced and Basic program areas.
Your DMV renewal notice tells you directly: it says either “Smog Certification Required” or “Smog Certification Required at a STAR station”. Read the notice before choosing a station — if it says STAR, a regular station won’t count.
Change of ownership
When a car is sold, the seller must provide the buyer a valid smog certification — obtained within 90 days of the sale.
Exception: if the vehicle is 4 or fewer model years old, no inspection is needed at all. For 2026, that means 2022 and newer — the buyer simply pays an $8 smog transfer fee to the DMV instead.
First California registration of an out-of-state vehicle
Bringing a car in from another state? A smog check is required for initial California registration — regardless of program area. Our new-resident smog check guide covers the whole first-registration process — the test, the 7,500-mile rule, and the 20-day clock.
Important: the 8-year new-vehicle exemption does NOT apply to nonresident vehicles being registered in California for the first time. Even a brand-new car from another state must be tested. New residents must also register within 20 days of establishing residency.
Which California counties require smog checks? (all 34)
Smog checks are required in these 34 counties:
Vehicles that don’t need a smog check
Per dmv.ca.gov, your vehicle does not need a smog inspection if it falls into one of these categories.
Gasoline, 1975 & older
Gasoline-powered vehicles from model year 1975 and older are exempt — this includes motorcycles and trailers of that era.
Diesel, 1997 & older
Diesel-powered vehicles from 1997 and older are exempt, as are any diesels with a gross vehicle weight over 14,000 lbs.
Natural gas over 14,000 lbs
Natural gas–powered vehicles weighing over 14,000 lbs do not need a smog inspection.
Electric vehicles
Fully electric vehicles are completely exempt — no inspection and no smog abatement fee.
Gasoline under 8 model years
Gasoline-powered vehicles less than 8 model years old skip the test at renewal. Instead of a test, you pay a smog abatement fee with your registration.
Motorcycles
Motorcycles are exempt from California smog checks entirely.
Diesel nuance — read this
The 8-year and 4-year new-vehicle exemptions do NOT apply to diesels. A brand-new diesel (1998+) still needs a smog check at its first biennial renewal.
Smog abatement fee
Vehicles less than 8 model years old pay an annual smog abatement fee with registration instead of testing (since January 2019). The amount is set by the DMV — check the current fee schedule. Rule of thumb: add 8 to your model year (a 2020 model gets its first smog check at its 2028 renewal).
Good to know: there is no smog exemption for military members or veterans — a smog check is still required. Hybrids have been subject to smog checks since April 2015 with the same 8-year exemption as gasoline cars, but plug-in hybrids are not exempt.
What is a STAR smog check station?
STAR stations meet higher BAR performance standards — and sometimes your renewal notice requires you to use one.
The STAR program
STAR began January 1, 2013, replacing the old Gold Shield and Test Only programs. A STAR station meets higher performance requirements set by the Bureau of Automotive Repair and can inspect all vehicles — including high-polluting ones. If your DMV renewal notice says “Smog Certification Required at a STAR station,” a certificate from any other station won’t count.
When you’re sent to a STAR station
You’re directed to STAR if your vehicle has a high-emitter profile, was randomly selected for quality control, or previously failed a smog check. It’s not a punishment — it’s how BAR keeps the program honest.
The gross polluter rule
Vehicles that fail as gross polluters must be repaired and re-certified at a STAR station or BAR Referee — a regular test-and-repair station can’t sign off on them.
Find a smog check near me
Don’t guess from reviews — use the Bureau of Automotive Repair’s own locator to find a licensed smog test near you.
Check your DMV notice first
Before you search, look at your renewal notice. If it says “Smog Certification Required at a STAR station,” filter your search for STAR stations only — a test from anywhere else won’t satisfy the requirement.
Use the BAR Auto Shop Locator
The BAR Auto Shop Locator (launched August 2020) is a mobile-friendly map tool at bar.ca.gov. Search by zip code or city — it shows test-only, test-and-repair, and STAR stations, so you pick exactly the type you need.
Know the station types
Test-and-repair stations do smog checks and emissions repairs. Test-only stations inspect only — they can’t do repairs, so the test is unbiased. Repair-only stations fix emissions issues but don’t inspect.
Walk in or book ahead
Most stations accept walk-ins — no appointment is needed for a smog check. That said, appointments are available at many stations and can cut your wait at busy STAR locations.
Open the BAR Auto Shop Locator
We never recommend specific stations by name — use the official BAR locator above so you’re always looking at currently licensed shops.
How much is a smog check in California?
Inspection prices are not regulated by BAR — stations set their own fees. Here’s what the data says.
The $8.25 certificate fee
This is a state-mandated fee, charged only if your vehicle passes. It goes to the DMV, and your certificate is transmitted electronically — it’s valid for 90 days. No pass, no fee.
What pushes the price up
STAR stations may charge slightly more than regular stations, and diesel smog checks often cost more than gasoline. Older vehicles that need tailpipe testing can also land toward the higher end.
Smog check cost estimator
Pick your vehicle type for a realistic cost range.
What happens during a smog check — and how long does it take?
A smog check takes about 20–30 minutes total (15–20 for newer OBD-II vehicles) and has three parts.
1. Visual inspection
The technician checks that emissions control equipment is present and unmodified. Aftermarket parts must have CARB executive-order approval.
2. Functional OBD check
The onboard diagnostics system is scanned — check engine light status and emissions monitors are verified electronically.
3. Tailpipe emissions test
Older vehicles get an actual tailpipe emissions measurement; 1996 and newer vehicles are evaluated through OBD-II instead.
Check engine light on = automatic fail. Get the underlying issue fixed before you go in — otherwise you’re paying for a test you can’t pass. Tip: drive 15–20 minutes beforehand to warm up the engine and catalytic converter. You don’t need to bring any paperwork — the tech enters your VIN and plate directly, though bringing your DMV renewal notice (barcode scan) speeds things up.
What to do if your car fails the smog check
A failure isn’t the end of the road — and if money is tight, the state may help pay for repairs.
Repair and retest
You get a Vehicle Inspection Report listing exactly why the car failed. Repair the named issues, then retest — your registration can’t renew until the vehicle passes. Some stations offer a free retest within a window; ask before you leave.
Gross polluter failures
Failed as a gross polluter? The car must be repaired and certified at a STAR station or BAR Referee. The BAR Referee (asktheref.org or (800) 622-7733) also handles dispute resolution, unusual vehicles, and repair cost waivers. BAR’s consumer line: (800) 952-5210.
Consumer Assistance Program (CAP) — repair help
If you failed a biennial smog check and your household income is at or below 225% of the federal poverty level, BAR’s Consumer Assistance Program (effective January 1, 2025) pays up to $1,450 toward repairs for model year 1996 and newer, or up to $1,100 for 1976–1995 models. Repairs are done at a CAP-authorized STAR test-and-repair station and you pay a co-payment — and you can now receive repair assistance more than once for the same vehicle.
Apply FIRST at bar.ca.gov or (866) 272-9642 — BAR will not reimburse repairs started before your eligibility letter arrives.
CAP vehicle retirement — even if your car passes
You can retire a vehicle through CAP even if it passes: $2,000 for income-eligible owners whose car failed its most recent check, $1,500 for income-eligible owners whose car passed or failed within the past 180 days, or $1,350 with no income requirement if it failed its most recent check. The vehicle must run and drive to the dismantler under its own power, have been continuously registered for 2 years (no lapse over 120 days), and weigh 10,000 lbs GVWR or less.
Warning: if you’re seeking CAP assistance, do not authorize any repairs before your CAP eligibility is approved — repairs started early won’t be reimbursed.
How to Prepare Your Car to Pass the First Time
Most smog failures aren’t mysteries — they’re avoidable. Smog technicians across California repeat the same advice: a little preparation eliminates the failures that have nothing to do with how clean your car actually runs.
- Fix the check engine light first. A lit check engine light is an automatic fail in California — no exceptions. The most common culprit is a faulty or “lazy” oxygen sensor, which is usually an inexpensive repair.
- Drive 15–20 minutes at highway speed right before the test. This heats the catalytic converter to full operating temperature, when it cleans exhaust most effectively.
- For two weeks before the test, avoid short-trip-only driving. If the catalytic converter never gets hot enough, residues build up instead of burning off.
- Change the oil if it’s dirty. Hydrocarbons from old, dirty oil seep into the combustion chamber and raise your readings.
- Check the air filter. Hold it up to a light — if no light passes through, replace it. Most filters need replacement every 12,000–15,000 miles.
- Inflate your tires to the manufacturer’s spec. On the dynamometer (roller) portion of the test, incorrect tire pressure skews the readings.
- Arrive with at least half a tank of quality fuel. Don’t roll in on fumes — fuel system pressurization matters for the evaporative emissions check.
- Schedule any tune-up at least two weeks ahead — never days before the test. Fresh repairs can unset the car’s readiness monitors (see the battery trap below).
None of this guarantees a pass on a car with genuine emissions faults — but it eliminates the avoidable failures that send thousands of Californians back for a retest every month.
The Battery Trap: Why a Recent Battery Change Fails Your Smog Test
This is one of the most common — and most surprising — reasons Californians fail: the car is perfectly fine, but a dead or recently replaced battery wiped the computer’s memory.
Your car’s onboard computer runs continuous self-checks called readiness monitors. When the battery dies or is disconnected, those monitors are erased. At the smog station, the result reads “not ready” — and in California, “not ready” is a fail, even if the car would otherwise pass.
- The fix: drive 150–200 miles of mixed city and highway driving over several days. The monitors reset as the computer completes its drive cycles — there’s no shortcut.
- Prevention: when replacing a battery, ask the shop to use a memory saver (a small device that plugs into the OBD-II port or cigarette lighter) to keep the computer powered during the swap.
- Verify before you go: a basic OBD-II scanner (or many auto parts stores, free of charge) can confirm all monitors read “ready” before you pay for a test.
Rule of thumb: if you’ve had battery work, a jump-start, or any repair that disconnected power in the last couple of weeks, wait and drive before testing.
Repair Cost Waiver: When $650 in Repairs Earns You a Pass
If your car fails and repairs are getting expensive, California offers a one-time escape hatch — the Repair Cost Waiver.
Under California Code of Regulations, Title 16, §3340.43, you can qualify for a waiver if you’ve already spent at least $650 on emissions-related repairs at a licensed station and the car still won’t pass. (BAR adjusts the threshold periodically for inflation, so confirm the current figure before you apply.)
- How to apply: through a Smog Check Referee — call 1-800-622-7733 or visit asktheref.org to make an appointment.
- Bring: your failed Vehicle Inspection Report (VIR), repair receipts totaling $650 or more, and current registration.
- The test fee itself does not count toward the $650 — only actual repair spending.
- Money spent through the Consumer Assistance Program (CAP) counts toward the threshold.
- One-time only: one waiver per vehicle, per registered owner — and the car must fully pass at its next biennial inspection.
Not eligible: vehicles failed as gross polluters, vehicles with tampered emissions equipment, and — importantly — the waiver is not available for change-of-ownership or initial California registration smog checks. Those must pass outright.
Temporary Operating Permit (TOP): Driving Legally While You Repair
Failed the test and your registration is due? You may not have to park the car — a Temporary Operating Permit can keep you legal while repairs happen.
A TOP is exactly what it sounds like: a bridge, not a permanent solution. It lets you drive for a limited time while you get the car repaired and retested.
- Cost: about $50 in biennial smog counties — and free for initial registration or title-transfer situations. (Fees change; confirm the current amount with the DMV.)
- You’ll need: a copy of the failed smog test, proof of insurance, and payment of your renewal or transfer fees.
- Where: issued through the DMV — ask specifically for a Temporary Operating Permit tied to your smog repair situation.
Don’t confuse a TOP with permission to skip the repair. The car still has to pass before your registration completes — the permit just buys you lawful driving time to get there.
7 Common Reasons Cars Fail (and What They Mean)
Technicians see the same failures over and over. If your car failed, the cause is probably on this list.
| Failure reason | What’s happening | Typical fix |
|---|---|---|
| Check engine light is on | Automatic fail — the light means the computer detected an emissions fault | Diagnose the code; often a faulty oxygen sensor |
| Lazy or faulty O2 sensor | The sensor responds too slowly, so fuel mixture stays off | Replace the oxygen sensor |
| Rich fuel mixture | Too much fuel, not enough air — often a bad mass airflow (MAF) sensor or leaking fuel injectors | Clean or replace MAF sensor; service injectors |
| Clogged air filter | Restricted airflow throws off the air-fuel ratio | Replace the filter (every 12k–15k miles) |
| Catalytic converter failure or theft | The cat can’t clean exhaust — or it’s simply gone (a major California problem) | Replace with OEM or CARB-approved converter only |
| Gas cap / EVAP system leak | The fuel system can’t hold pressure; vapors escape | Replace gas cap; smoke-test the EVAP system |
| Readiness monitors “not ready” | Recent battery disconnect or repair erased the computer’s self-checks | Drive 150–200 miles, then retest |
A California-specific note: catalytic converter theft is rampant in the state. A replacement converter must be OEM or CARB-approved — a cheap universal converter will fail the visual inspection even if the tailpipe numbers look fine.
The Partial-County Catch: 6 Counties Where Smog Depends on Your Zip Code
California’s smog program covers 34 counties — but in 6 of them, whether you need a smog check depends on your exact zip code.
These counties are only partially included in the program, typically because the cleaner rural or mountain areas are exempt while the more populated areas are not:
- Sonoma County
- San Bernardino County
- El Dorado County
- San Diego County
- Placer County
- Riverside County
How to know for sure: your registration renewal notice from the DMV states whether a smog certification is required — and BAR’s website lets you check by zip code. If you just moved within one of these counties, don’t assume the rule followed you; verify.
What Smog Checks Actually Cost in 2026 (BAR Data)
California doesn’t regulate what stations charge, so prices vary — but the Bureau of Automotive Repair publishes real averages.
- Statewide average (July 2026 BAR report): $69.54 per inspection.
- Test type matters: older tailpipe-style BAR-97 inspections averaged $72.83, while modern OBD inspections averaged $66.25.
- First-test failure rate: 8.35% of vehicles fail their first test — roughly 1 in 12.
- The $8.25 certificate fee is charged only when your car passes, on top of the inspection price.
Prices are set by each station, so it pays to compare — but beware of prices that seem too good to be true paired with pressure to buy “needed” repairs on the spot. A test-only station has no incentive to upsell you repairs, which is one reason many drivers prefer them.
Seller Didn’t Give You a Smog Certificate? Your Rights
In California, providing a valid smog certificate (from a test within the last 90 days) is the seller’s legal responsibility — not the buyer’s.
This surprises a lot of buyers, especially in private-party sales. Key points:
- An “as-is” clause does not override the seller’s smog obligation. Even if the bill of sale says “as-is,” the seller is still on the hook for the certificate in most private sales.
- Limited exceptions exist — for example, certain transfers between family members and vehicles exempt from the biennial program. A standard sale between strangers is not one of them.
- Your recourse is breach of contract — not lemon law (which covers dealer sales of newer vehicles). You can demand the seller pay for the smog repair, refund part of the price, or take the deal back.
Practical steps if this happened to you: (1) contact the seller in writing and request they cover the smog certification; (2) file a complaint with the Bureau of Automotive Repair if a licensed dealer or station is involved; (3) for private sellers who refuse, small claims court handles disputes up to $10,000 in California. Keep every document — the bill of sale, the failed VIR, and all repair receipts.
Federal Emissions Warranty: Free Repairs You May Not Know About
Before paying for emissions repairs out of pocket, check your federal emissions warranty. Under federal law, manufacturers must cover specific emissions components for 8 years or 80,000 miles (whichever comes first). This includes the catalytic converter, engine control module, and onboard diagnostics system.
Many California drivers pay for catalytic converter replacements that should have been free under this warranty. Check your owner’s manual or call your dealer with your VIN to verify coverage before authorizing repairs.
What to Bring to Your Smog Check
Keep it simple — you don’t need much:
- Your vehicle — obviously! Drive it for 15-20 minutes beforehand to warm up the catalytic converter.
- Renewal notice (if you have it) — helps the technician, but not required. They can look up your vehicle by plate/VIN.
- Payment — most stations accept cash and cards. Ask about the total price (test + $8.25 cert fee if you pass) before they start.
You do not need to bring your registration card, proof of insurance, or ID for a standard smog check — though having them doesn’t hurt.
How to Read Your Vehicle Inspection Report (VIR)
After your test, you’ll receive a Vehicle Inspection Report (VIR). Here’s what the key sections mean:
- Overall Result: PASS, FAIL, or ABORT — the bottom line.
- Emissions measurements: Your car’s actual readings vs. the maximum allowed (cutpoints). If you failed, the specific pollutant that exceeded limits tells your mechanic where to look.
- Visual/functional checks: Confirms your check engine light, gas cap, and emissions equipment are present and working.
- OBD-II readiness: Shows whether your car’s computer monitors are “ready.” If “not ready,” you need more driving before retesting.
Keep your VIR — you’ll need it if applying for a repair cost waiver or CAP assistance. Learn more in our failed smog check guide.
Explore Smog Check Topics in Depth
Dive deeper into specific smog check topics:
- Smog Check Cost in California — detailed pricing breakdown
- What to Do If You Fail — repairs, waivers, and next steps
- Smog Check Exemptions — full list of who doesn’t need one
- Jay Leno’s Law (SB 1392) — the new classic-car exemption and its 2028–2033 phase-in, explained
- Diesel Smog Checks — diesel-specific requirements
- Check Your Smog History — look up past results
- Smog Check When Selling — seller responsibilities
- How Often You Need One — biennial cycle explained
- What to Expect — step-by-step walkthrough
- STAR Stations Explained — what STAR certification means
Smog check questions, answered
The questions Californians ask most about smog checks — answered from official sources.
How long does a smog check take?
About 20–30 minutes total (15–20 for newer OBD-II vehicles). Most stations accept walk-ins, so the test itself is quick — just allow a little extra time if the station is busy.
How much is a smog check in California?
Typically $30–$90, with the average around $69 (BAR July 2026 average: $69.54) (BAR 2025/2026 data). The $8.25 state certificate fee is added only if you pass. Prices aren’t regulated — stations set their own fees, so call ahead to compare.
Do I need an appointment for a smog check?
No. Most stations accept walk-ins, though appointments can cut wait times at busy STAR stations.
What do I need to bring to a smog check?
Nothing is required. The technician enters your VIN and license plate directly into the smog machine; bringing your DMV renewal notice speeds things up via its barcode scan.
How do I find a smog check station near me?
Use BAR’s Auto Shop Locator at bar.ca.gov — search by zip code or city on the map. It shows test-only, test-and-repair, and STAR stations.
What is a STAR smog station?
A station meeting higher BAR performance standards (in place since January 1, 2013). You must use one if your DMV notice says “Smog Certification Required at a STAR station.”
Why was I sent to a STAR station?
Your vehicle is a high-emitter-profile model, was randomly selected for quality control, or previously failed a smog check.
Will my car pass with the check engine light on?
No — a check engine light that’s on is an automatic fail. Fix the underlying issue first, then retest.
What happens if my car fails the smog check?
You get a Vehicle Inspection Report listing the failure reasons. Repair the named issues, then retest. Your registration can’t renew until the vehicle passes.
Is there financial help for smog repairs?
Yes: BAR’s Consumer Assistance Program pays up to $1,450 toward repairs for income-eligible owners (or $1,100 for 1976–1995 models), or $1,350–$2,000 to retire the vehicle. Apply at bar.ca.gov or (866) 272-9642 BEFORE authorizing any repairs.
What is the smog abatement fee?
Instead of a test, gasoline and hybrid vehicles less than 8 model years old pay an annual smog abatement fee with their registration (in place since January 2019). The exact amount is set by the DMV — check the current fee schedule.
Do hybrid cars need smog checks?
Yes — hybrids have been subject to smog checks since April 2015, with the same 8-year new-vehicle exemption as gasoline cars. Plug-in hybrids are not exempt.
Do diesel trucks need smog checks?
Diesels from 1998 and newer at 14,000 lbs or less: yes, every 2 years — with NO new-vehicle exemption. Diesels from 1997 and older are exempt.
Do electric cars or motorcycles need smog checks?
No — both are fully exempt.
I’m a new California resident. Do I need a smog check?
Yes — out-of-state vehicles need a smog check for initial California registration (the 8-year exemption doesn’t apply), and you must register within 20 days of establishing residency.
How long is a smog certificate valid?
90 days, transmitted electronically to the DMV.
Who pays for the smog check when selling a car?
The seller must provide a valid certificate. If the car is 4 or fewer model years old, no test is needed — the buyer pays an $8 smog transfer fee to the DMV instead.
Can I still drive if my car fails?
You can’t renew your registration until the vehicle passes. The DMV may issue a temporary operating permit while you repair — check current DMV rules on temporary permits before relying on this.
Find a smog test near you today
Search the official BAR Auto Shop Locator by zip code or city — it shows test-only, test-and-repair, and STAR stations. Most take walk-ins, and the test takes 20–30 minutes.
Last verified against dmv.ca.gov and bar.ca.gov: October 15, 2026.