Smog Check inspections

Smog Check inspections are performed by licensed stations and inspectors using one of two different vehicle inspection systems depending on the inspected vehicle’s age, weight, and fuel type. The BAR On-Board Diagnostic Inspection System (BAR-OIS) is primarily used to collect electronic emissions control system data from model year 2000 and newer vehicles. The BAR-97 Emissions Inspection System (BAR-97 EIS) is primarily used to measure tailpipe emissions on model year 1999 and older vehicles.

Smog Check Manual

The Smog Check Manual provides the procedures for performing Smog Check inspections and issuing certificates of compliance. It also details important equipment requirements for the BAR-OIS and BAR-97 EIS.

Smog Check Manual 

Reference guides

Smog Check Reference Guide - Reference information on the Smog Check Program, repair and retest procedures, Referee services, engine changes, and more

On-Board Diagnostic Test Reference - A summary of pass/fail standards and instructions for inspecting vehicles with known test difficulties

Acceleration Simulation Mode emissions standards - Search Acceleration Simulation Mode emissions standards by vehicle make, model year, and body type

Two-speed idle cutpoints - Cutpoints for vehicles tested using the two-speed idle test on the BAR-97 EIS

Station checklist

Use the station checklist to help ensure your station has the equipment, tools, and reference materials required to perform Smog Check inspections.


Certificates of compliance

Certificates of compliance can be purchased conveniently through the BAR-OIS and BAR-97 EIS.

For BAR-OIS: Make sure your station has registered and downloaded the Cal-VIS software to your BAR-OIS and completed the online enrollment and participation agreement through the Cal-VIS billing portal before purchasing certificates.

To order certificates by mail, complete a Certificate Order Form. To request a refund of unused certificates, complete a Certificate Refund Request.

STAR program

The STAR program is a voluntary program for stations seeking to inspect directed vehicles. Stations and technicians participating in the program must adhere to high inspection-based standards. These quality inspections are critical in helping the state meet required emissions reductions.

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Aftermarket, performance, and add-on parts

Clean Truck Check - Heavy-Duty Inspection and Maintenance Program

Training tutorials