(a) The manufacturer of each motor vehicle or motor vehicle engine manufactured prior to the 1990 model-year shall warrant to the ultimate purchaser and each subsequent purchaser that the motor vehicle or motor vehicle engine is:

1. (1) Designed, built, and equipped so as to conform, at the time of sale, with the applicable emission standards specified in this part.
2. (2) Free from defects in materials and workmanship which cause such motor vehicle or motor vehicle engine to fail to conform with applicable regulations for its useful life, determined pursuant to subdivision (b).

(b) As used in subdivision (a), “useful life” of a motor vehicle or motor vehicle engine means:

1. (1) In the case of light-duty motor vehicles, and motor vehicle engines used in such motor vehicles, a period of use of five years or 50,000 miles, whichever first occurs, except that, in the case of fuel metering and ignition systems and their component parts which are contained in the state board’s “Emissions Warranty Parts List” dated December 14, 1978 (items I(A), I(C), III(A), III(C), III(E), IX(A), and IX(B)), and which are contained in vehicles or vehicle engines certified to the optional standards pursuant to Section 43101.5 and subject to subdivision (a) of Section 43009.5, “useful life” means a period of use of two years or 24,000 miles, whichever occurs first.
2. (2) In the case of any other motor vehicle or motor vehicle engine, a period of use of five years or 50,000 miles, whichever first occurs, unless the state board determines that a period of use of greater duration or mileage is appropriate.