First, let's look at the three sections the Smog Inspection consists of:

	Emissions Inspection
	The Visual Inspection
	The Functional Inspection

NOTE: 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 Nitrous 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.

New "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 dynomometer.

If your engine is carbureted it will look similar to the engines below and will require a pre-heat tube. Frequent removal and installation of the air cleaner often causes the pre-heat tube to be misplaced and/or lost. You should inspect your engine and insure this component is present and in good shape.

Note: Counties in California with low smog pollution still maintain 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.

New "OBDII" Smog Machine Link - The State of California now       requires all vehicles 1996 and up, to communicate directly with the smog machine during the smog test. This is achieved via your vehicle's OBDII Data Link Connecter. As part of the smog inspection process, the smog technician will connect a Data Cable from the smog machine to your vehicle's OBDII Data Link Plug. This cable will deliver important "Check Engine" codes and "Readiness Flags" from the engine's computer system to the state's smog machine. Emissions related failure codes will cause your vehicle to fail the smog inspection. The failure codes will be printed on the Vehicle Inspection Report (VIR) which will be given to you by the smog station.