California’s Smog Check program reduces vehicle emissions and enhances air quality. This mandatory inspection ensures vehicles meet environmental standards for registration. Understanding the requirements helps vehicle owners comply and contribute to cleaner air by identifying vehicles with excessive pollutants.
Understanding Smog Checks
A smog check inspects a vehicle’s emission control systems to minimize harmful pollutants released into the atmosphere. This process ensures cars operate within established emission limits, addressing air quality concerns. Pollutants like carbon monoxide, nitrogen oxides, and hydrocarbons contribute to smog, negatively impacting respiratory health and the environment.
The Bureau of Automotive Repair (BAR) administers the smog check program under the California Vehicle Code. BAR oversees licensed stations and technicians, ensuring consistent testing standards. This mandatory program applies to most vehicles in California, regularly assessing their environmental performance.
Vehicles and Smog Check Requirements
Most gasoline-powered, hybrid, and alternative-fuel vehicles from the 1976 model year and newer are subject to California’s smog check requirements. Smog inspections are generally required every two years for registration renewal in most California counties. A smog check is also mandated when a vehicle changes ownership or when an out-of-state vehicle is initially registered in California.
Several exemptions exist based on vehicle type and model year:
Gasoline vehicles from the 1975 model year and older.
Newer gasoline vehicles (eight model years old or newer) for registration renewal (an annual smog abatement fee is paid instead).
Gasoline vehicles (four model years old or newer) for a change of ownership (the new owner pays a smog transfer fee).
Electric vehicles.
Motorcycles.
Diesel-powered vehicles from the 1997 model year and older.
Diesel-powered vehicles with a Gross Vehicle Weight Rating (GVWR) exceeding 14,000 pounds.
The Smog Check Process
To begin the smog check process, vehicle owners locate a certified smog check station, which can include “Test-Only” or “Test-and-Repair” facilities. Some vehicles may be directed to a “STAR station,” which meets higher performance standards. The inspection typically involves a visual inspection of emission control components, functional tests of systems like ignition timing and exhaust gas recirculation, and an emissions test.
For vehicles model year 2000 and newer, the emissions test primarily involves an On-Board Diagnostic (OBD) system check, which accesses the vehicle’s computer for emissions data. Older vehicles, pre-2000, may undergo a tailpipe emissions test using a dynamometer, where the vehicle is run on rollers to simulate driving conditions. Before the test, ensure the “Check Engine” light is off, as an illuminated light results in automatic failure. Driving the vehicle for 15 to 20 minutes beforehand allows the engine to reach optimal operating temperature and helps the diagnostic system complete its checks.
What to Do After a Smog Check
After a smog check, the outcome dictates the next steps. If a vehicle passes, the smog certificate is electronically submitted to the Department of Motor Vehicles (DMV) by the testing station. This electronic submission allows the vehicle owner to proceed with registration renewal or complete a change of ownership.
If a vehicle fails the smog check, the inspection report will detail the specific reasons for the failure, including emission levels or diagnostic trouble codes. Owners must then have the necessary repairs performed by a licensed technician. After repairs, the vehicle must undergo a retest to verify that the issues have been resolved and it now meets emission standards. The Bureau of Automotive Repair (BAR) offers a Consumer Assistance Program (CAP) which may provide financial assistance for emissions-related repairs for eligible vehicle owners, or an incentive for vehicle retirement.