Frequently Asked Questions
Motor homes with a Gross Vehicle Weight Rating (GVWR) of 8,501 pounds or more are excused from dynamometer testing. Your Smog Check technician will be able to give any such vehicle the two-speed idle test. Some motor homes with a GVWR of less than 8,501 pounds still may not be safe for dynamometer testing. If your Smog Check technician decides he or she cannot safely test your motor home on the dynamometer, they should write that on your invoice. A State Referee facility can provide relief in these circumstances. Make an appointment at a Referee Facility. Take your invoice to the Referee. If the Referee inspector agrees, he or she will test the vehicle using a two speed idle test.
For gas-powered vehicles the 1976 model year is the earliest model year vehicle required to participate in the biennial Smog Check Program. Vehicles six years old and newer are not required to participate in the biennial Smog Check Program. For diesel-powered vehicles 1998 model year and newer 14,000 lbs and less are subject to the biennial Smog Check Program. The six year exemption does not apply to diesel vehicles.
Many 1976 model vehicles were built in 1975; however, the Smog Check exemption is based on model year, not date of manufacturer, so these vehicles are not exempt.
A gas-powered vehicle is excused from Smog Check until it is seven model years old. DMV computers are designed to recognize the exemption and process your renewal accordingly. Go back the DMV to resolve this problem. If you are unable to resolve the problem with DMV, the State Referee can help. Make an appointment at the nearest Referee facility. Note: A Smog Check certificate of compliance is required upon transfer of ownership for gas-powered vehicles that are older than four model years.
No, the Smog Check is only for operational vehicles. However, if you miss your biennial Smog Check while the vehicle is non-operational, you will be required to get a smog inspection prior to bringing the vehicle back to operational status.
The Bureau of Automotive Repair does not set the price of smog inspections. Smog Check stations are privately owned and operated businesses, and as such, determine the fees for their time and expertise based on free-market forces. As with many other things, it pays to shop around for your Smog Check. You can search our list of Active Smog Check stations by city, ZIP code and station type to find a station near you
Not all vehicles are compatible with the dynamometer. Vehicles with full-time four wheel drive, with non-disengageable traction control, or with a Gross Vehicle Weight Rating 10,000 pounds or greater (motor homes 8501 GVWR or greater), are not tested on the dynamometer.
Motorists who believe their vehicles may not pass initial smog certification at local Smog Check stations may request that an inspection be conducted before an official smog certification test. This procedure can help vehicle owners avoid their vehicles being designated as "Gross Polluters," requiring final inspection at a Test-Only Center or a Gold Shield station. Smog Check stations may charge for this service only if authorized by the consumer; BAR does not regulate those charges and receives none of the proceeds. The effectiveness of this program is subject to periodic review. Motorists should keep in mind that neither the pre-inspection (which is not an "official" inspection), nor any emissions repairs made subsequent to the preinspection, count toward the $450 repair cost waiver
In order for your vehicle to receive a Smog Check certificate, it must pass all the following elements of a Smog Check inspection:
- A visual inspection, in which required emissions control components and systems are identified, and must appear connected and functional.
- A functional inspection which includes, as applicable, checking the functionality and/or integrity of the emissions control malfunction indicator light ("Check Engine", etc), the ignition timing, the gas cap, and the Exhaust Gas Recirculation (EGR) system, if the vehicle is so equipped and a Two-Speed Idle (TSI) test is being performed. A Low Pressure Fuel Evaporative Test (LPFET) is performed on all 1995 and older vehicles. A functional check of a vehicle's On-Board Diagnostic (OBD) system is also performed on 1996 and newer vehicles. Diagnostic information stored in the vehicle's computer is reported on the Vehicle Inspection Report (VIR) that the motorist receives at the end of the Smog Check inspection. OBD information can save time and money when repairs are required.
- A tailpipe emissions test, which measures exhaust emissions using a probe inserted into the vehicle's tailpipe during testing. Vehicles pass or fail this part of the Smog Check inspection based on established emission standards, sometimes called cut points.
A. The tailpipe test alone cannot guarantee that a car is not emitting harmful amounts of pollutants into California's air. In fact, to obtain a Smog Check certificate, a vehicle must pass all three portions of the Smog Check inspection-the visual, functional and tailpipe inspections (see previous question). An "underhood" inspection comprises the visual and functional portions of the Smog Check inspection. The visual inspection ensures that the vehicle has all of the proper equipment and that none of its parts are disconnected or modified. The visual inspection helps prevent evaporative emissions. These occur even when the vehicle is parked, and may be the result of poorly connected or improper equipment. On the old, two-speed idle (TSI) test, the functional inspection ensures that the ignition timing is set to the manufacturer's specifications and that the EGR valve is functioning. The functional portion of the TSI test is especially important because the tailpipe inspection cannot measure oxides of nitrogen (NOx) emissions-a key precursor to smog. The EGR test is not a part of the new dynamometer test, because that test does measure for NOx. The newest part of the functional test is the fuel cap test, which is used to help prevent evaporative emissions. The visual and functional tests help identify vehicles with tampered emissions control systems. These vehicles may be configured to pass the tailpipe portion of the Smog Check inspection, but altered later to produce more emissions than allowed. This gave the previous program the reputation of passing vehicles which were "clean for a day," rather than clean until the vehicles' next Smog Check. Vehicles which were only "clean for a day" hindered California from meeting its clean air goals.
Win general, state and federal law prohibit modifications to your vehicle's emission control system. When repairing your vehicle, the emission-related parts used must be original equipment manufacturer (OEM) parts or be replacements for the OEM parts, as specified by the part manufacturer. Modifications to your emissions controls are not acceptable unless the parts used are approved/exempted by the California Air Resources Board. The California Air Resources Board (CARB) grants exemptions in cases where the changes do not modify the performance of the emission controls in a way that causes an increase in emissions. CARB assigns the exempted parts an "executive order" (EO) number that may be used to verify acceptability. CARB provides a listing of EO exempted parts on the CARB website. Minor changes that do not affect the connectivity with or operation of other emission controls may be acceptable, for example,the installation of universal replacement hose in place of a preformed hose.
An engine change may not be performed if it degrades the effectiveness of a vehicle's emission control system. For more information, see BAR's Engine Change Guidelines. The following apply to any modifications or deviations from the original emission control configuration:
- You must use Original Equipment Manufacturers (OEM) specification parts for use in your specific year, make, and model of vehicle. OR
- The part must have an Executive Order (EO) number that shows it has been exempted by the California Air Resources Board for use in your vehicle. OR
- The equipment used must be certified by the U.S. Environmental Protection Agency (USEPA) for use in your specific year, make, and model of vehicle.
Check out the Bureau's BAR's Engine Change Guidelines. brochure on this Web site for additional information.
The only emissions-related repairs which count toward the $450 minimum are those completed by a licensed smog technician in a licensed smog station after the vehicle has failed a smog test. Although BAR does not discourage the home mechanic from making the necessary emissions repairs to his or her vehicle, home repairs do not qualify as credit toward the $450 minimum.
Inclusion of light-duty diesel-fueled vehicles was considered during development of the Smog Check Program and they may be included in the future. Testing methods and strategies are still under evaluation at this time.