Section 86.090-5 - General standards; increase in emissions; unsafe conditions(a)(1) Every new motor vehicle (or new motor vehicle engine) manufactured for sale, sold, offered for sale, introduced, or delivered for introduction to commerce, or imported into the United States for sale or resale which is subject to any of the standards prescribed in this subpart shall be covered by a certificate of conformity issued pursuant to §§ 86.090-21 , 86.090-22 , 86.090-23 , 86.090-29 , 86.090-30 , 86.079-31 , 86.079-32 , 86.079-33 , and 86.082-34 .(2) No heavy-duty vehicle manufacturer shall take any of the actions specified in section 203(a)(1) of the Act with respect to any Otto-cycle or diesel heavy-duty vehicle which uses an engine which has not been certified as meeting applicable standards.(3) Notwithstanding paragraphs (a) (1) and (2) of this section, a light or heavy duty motor vehicle equipped with an engine certified to the nonroad provision of 40 CFR part 89 may be sold, offered for sale or otherwise introduced into commerce by a motor vehicle manufacturer to a secondary manufacturer if the motor vehicle manufacturer obtains written assurance from the secondary manufacturer that such vehicle will be converted to a nonroad vehicle or to a piece of nonroad equipment, as defined in 40 CFR part 89, before title is transferred to an ultimate purchaser. Failure of the secondary manufacturer to convert such vehicles to nonroad vehicles or equipment prior to transfer to an ultimate purchaser shall be considered a violation of section 203(a) (1) and (3) of the Clean Air Act.(b)(1) Any system installed on or incorporated in a new motor vehicle (or new motor vehicle engine) to enable such vehicle (or engine) to conform to standards imposed by this subpart. (i) Shall not in its operation or function cause the emission into the ambient air of any noxious or toxic substance that would not be emitted in the operation of such vehicle (or engine) without such system, except as specifically permitted by regulation; and(ii) Shall not in its operation, function or malfunction result in any unsafe condition endangering the motor vehicle, its occupants, or persons or property in close proximity to the vehicle.(2) In establishing the physically adjustable range of each adjustable parameter on a new motor vehicle (or new motor vehicle engine), the manufacturer shall ensure that, taking into consideration the production tolerances, safe vehicle driveability characteristics are available within that range, as required by section 202(a)(4) of the Clean Air Act.(3) Every manufacturer of new motor vehicles (or new motor vehicle engines) subject to any of the standards imposed by this subpart shall, prior to taking any of the actions specified in section 203(a)(1) of the Act, test or cause to be tested motor vehicles (or motor vehicle engines) in accordance with good engineering practice to ascertain that such test vehicles (or test engines) will meet the requirements of this section for the useful life of the vehicle (or engine).(4) Manufacturers of engines equipped with vanadium-based SCR catalysts must design the engine and its emission controls to prevent vanadium sublimation and protect the catalyst from high temperatures as described in 40 CFR 1036.115(g)(2) .54 FR 14460, Apr. 11, 1989, as amended at 61 FR 58106, Nov. 12, 1996; 88 FR 4474 , Jan. 24, 2023