(a)  In addition to certifying devices which meet the standards set forth in, or established pursuant to, Sections 43602 and 43610, the state board shall adopt standards for certifying exhaust devices which achieve a reduction of the emission of hydrocarbons, carbon monoxide, and oxides of nitrogen from the exhaust of a motor vehicle substantially below the standards for any two pollutants set forth in, or established pursuant to, Section 43602 or 43610.

If, however, an exhaust device is shown to substantially reduce the emission of any two of the three pollutants, the state board may certify such a device, so long as the installation of such device in a motor vehicle does not increase the emission of the other pollutant in excess of the emission of that pollutant by the vehicle in the absence of such a device.

(b)  Devices certified pursuant to this section may be certified without regard to the provisions of subdivision (a) of Section 43604 or subdivision (a) of Section 43612.

(c)  After one or more such devices are initially certified, no device shall be certified pursuant to this section which is substantially less effective than any device previously certified, unless the state board determines, pursuant to a cost-benefit analysis, that such less effective device is also substantially less costly and therefore merits certification. Any subsequent certification of a more effective device shall not affect the certification of a previously certified device.

(d)  The state board may permit the installation of a device certified pursuant to this section in lieu of any certified motor vehicle pollution control device which is required to be installed pursuant to any other provision of state law, if the installation of such device on that particular classification of motor vehicles results in no greater emissions than if the required certified device were operative over the life of the vehicle. The applicant shall be responsible for proving compliance with this subdivision and with other applicable criteria. Certificates of compliance shall be required upon the installation of a device certified pursuant to this section and installed pursuant to this subdivision, as if it were a device required by any other provision of state law.

(Added by Stats. 1975, Ch. 957.)