What does a smog check check?

Asked By: Evangelino Arlegui | Last Updated: 2nd April, 2020
Category: automotive auto repair
3.9/5 (313 Views . 39 Votes)
Smog Checks are designed to measure the amount and type of pollutants your vehicle is emitting. A Smog Check may include any of the following tests: Functional inspection of the vehicle's check engine light, ignition timing, exhaust gas recirculation system, fuel evaporative system, and gas cap.

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Correspondingly, how do I know if my car will pass smog?

Here's How to Pass the California Smog Check

  • Check the “Check Engine” light. If your “Check Engine” light is on, that's an automatic smog test failure.
  • Make sure the battery hasn't been recently disconnected.
  • Get an oil change.
  • Get a tune-up—but not right before the test.
  • Fill up the coolant and gas tanks.
  • Drive fast two weeks before the test.
  • Get a pre-inspection.

One may also ask, how much is a smog check? It will normally range anywhere between $29.95 to $89.95 depending on the county you live in and the type of smog inspection your vehicle requires. This price may or may not include the State's Certificate Fee of $8.25, which is charged only and if your vehicle passes the test.

In this way, what does it mean for a car to be smogged?

Smog check, smog test and emission check all refer to the same thing: a test of vehicle and its engine emissions performed at a licensed smog testing facility. In 1990, the Clean Air Act gave the EPA its authority to oversee states with respect to emissions.

How do you cheat a smog test?

We will discuss those methods below.

  1. 6 Proven Methods for Passing an Emissions (Smog) Test:
  2. Warm up Your Car's Engine as Much as Possible.
  3. Use a Fuel Additive.
  4. Be Sure Your Tires Are Inflated to the High End of the Range.
  5. Change Your Oil Before Your Smog Check.
  6. If Your Check Engine Light Is On, Find a Way to Turn It off.

35 Related Question Answers Found

Will my car pass California smog check?

All gasoline-powered vehicles, new or used, being registered for the first time in California must pass the California Smog Check. A vehicle will fail the California Smog Check if it is not equipped with the originally required smog devices.

How old does a car have to be for no smog in California?

Does my vehicle qualify for a smog exemption? Smog inspections are required unless your vehicle is: Gasoline powered 1975 year model or older. Diesel powered 1997 year model and older or with a Gross Vehicle Weight rating (GVWR) of more than 14,000 lbs.

What will make a car not pass smog?

Any roughness in the performance of the engine will have an impact on the results of your smog test. Also, if your car smokes or over-heats, you may not pass the smog inspection. Smoke from the tailpipe and a hot running engine create high levels of harmful emissions. Be sure that your gas cap fits properly.

How do you pass a smog check with a new battery?

If you've recently replaced or charged your battery, put 100 to 200 miles on the car before taking a smog test. Battery charging or replacement can temporarily erase your car's memory chip.

How much does it cost to get a car to pass smog?


The normal price range of the average smog test is between $29.95 and $69.95 depending on the county you live in, the type of vehicle you own car, truck, van, SUV, or motorhome, and the type of smog inspection your vehicle requires.

Can you pass smog with a check engine light?

If your check engine light is on, you'll automatically fail your smog test. If you have a broken oxygen sensor, even with the check engine light off you'll fail your smog test. Before you test your car, bring it in to your local auto repair shop for a diagnosis and any necessary repairs.

Does premium gas help pass emissions test?

Higher octane fuel will help me pass.
People often have the misconception that how to pass a smog test is to use premium 91 octane fuel. 91 Octane fuel contains higher amounts of combustible chemicals, which means it's formulated to burn longer, in higher performance engines.

Is it legal to swap engines in CA?

Remember, the Referee Inspection program is a benefit for people who do engine swaps. The California smog laws on engine swaps (or engine changes) are consistent with common sense, safety, and emissions reduction. That is, if it is legal in California, then according to the EPA, it is legal in all other states.

What happens if you fail a smog test?

After You Fail the Emissions Test
If your vehicle fails to pass, the DMV will not register your vehicle, meaning you can't get a license plate to legally drive the car. Once you have these repairs made, you can take your vehicle back to the inspection station to have it looked at again and most likely pass inspection.

Will the smog exempt year change?


Smog check changes and new abatement fees - The law expands smog check exemptions to vehicles that are up to eight model years old. The law clarifies that any suspensions or delays reported prior to January 1, 2019, remain in effect.

How is smog formed?

The atmospheric pollutants or gases that form smog are released in the air when fuels are burnt. When sunlight and its heat react with these gases and fine particles in the atmosphere, smog is formed. It is purely caused by air pollution.

What is smog made of?

This kind of visible air pollution is composed of nitrogen oxides, sulphur oxides, ozone, smoke and other particulates. Man-made smog is derived from coal combustion emissions, vehicular emissions, industrial emissions, forest and agricultural fires and photochemical reactions of these emissions.

Why do I need a star smog check?

Why Do I Need a STAR Inspection
Generally, the state of California will require a STAR smog check for automobiles known to have previously failed a smog inspection or that have higher emissions and vehicles with high emission profile ratings designated by the Bureau of Automotive Repairs.

How long does a smog test take?

about 20-30 minutes

Can you pay your car registration without the smog check?


Technically you can't renew your vehicle's registration without a smog check, but you can pay your renewal fees. You may pay your vehicle registration renewal fees now without a smog check, but you'll receive your new registration card and sticker after a passing smog check is obtained.

Is smog check every year?

Your DMV Smog Check Renewal Notice. Most vehicles in California are required to pass a Smog Check every two years for registration renewal. You may take your vehicle to any Smog Check station, unless it requires a Smog Check at a STAR station.

Are smog checks free?

DO NOT go to a smog check station that does not offer a FREE re-test. You may feel that your car will definitely pass, or is fairly new. The computer on board of your vehicle, hoses, and wiring under the hood, are all part of a smog inspection as required by the State.