First, let's look at the three sections the California Smog Inspection
2000 Model Year & Newer: 2000 model year and newer vehicles (except vehicles 14,000 GVWR or greater) are exempt from the Emission Inspection portion of the smog check.
These vehicles are administered the new DAD OIS Smog Test which includes a visual smog check inspection and functional inspection for OBD II trouble codes and readiness monitors.
Specific Test Order: The State of California requires smog stations
to test vehicles in the specific order listed above. The first
inspection (emissions inspection) is performed by the exhaust
gas analyzer "smog machine". During this step of the smog
check inspection, the smog machine is looking for the presence
of Hydrocarbons, Carbon Monoxides and Nitrogen Oxides in your
vehicle's exhaust. These are the three (3) undesired chemicals
which are responsible for the production of SMOG. The next two
inspections, the visual and functional, will be performed both
by the smog technician and/or the smog machine.
In order to pass Califoria's emissions test, your vehicle must produce passing results in all three test section.
Enhanced Smog Test - In parts of California
where smog pollution is higher, vehicle owners are now
required to complete an "Enhanced" version of California's
smog test. The "Enhanced" smog test requires your vehicle to
be driven on a dynamometer while the smog machine collects
emissions samples from the tailpipe. The "Enhanced" smog test
has been proven to retrieve a more accurate sample of a
vehicle's emissions output, then it's predecessor, the "Basic"
smog test. The "Basic" smog test requires vehicles to be
tested, only at idle and 2500 rpms. "Basic" smog test vehicles
do not need to be driven on a
Basic Smog Test
- Counties in
California with low smog pollution require the "Basic"
smog test. If your county has been added to the "Enhanced"
smog test requirement list, the smog stations in your local
area will have the neccessary equipment to test your vehicle. No specific action will be required by the vehicle owner.
Change of Ownership - Counties with even less smog pollution are designated as "Change of Ownership" areas. In Change of Ownership parts of the state, smog checks are only required when a vehicle is bought or sold, and when a used vehicle is imported into the state of California.