(a) You are exempted from the tampering prohibition in Clean Air Act section 203(a)(3) (42 U.S.C. 7522)(a)(3) (“tampering”) if you satisfy all the provisions of this subpart.

(b) The tampering exemption provisions described in this subpart are differentiated based on the age of the vehicle/engine at the point of conversion as follows:

(1) “New and relatively new” refers to a vehicle/engine where the date of conversion is in a calendar year that is not more than one year after the original model year. See §85.510 for provisions that apply specifically to new and relatively new vehicles/engines.

(2) “Intermediate age” refers to a vehicle/engine that has not exceeded the useful life (in years, miles, or hours of operation) applicable to the vehicle/engine as originally certified, excluding new and relatively new vehicles/engines. See §85.515 for provisions that apply specifically to intermediate-age vehicles/engines.

(3) “Outside useful life” refers to any vehicle/engine that has exceeded the useful life (in years, miles, or hours of operation) applicable to the vehicle/engine as originally certified. See §85.520 for provisions that apply specifically to outside useful life vehicles/engines.

(c) If the converted vehicle/engine is a dual-fuel or mixed-fuel vehicle/engine, you must submit test data using each type of fuel, except that if you wish to certify to the same standards as the OEM vehicle/engine, you may omit testing for the fuel originally used to certify the vehicle/engine if you comply with §85.510(b)(10)(ii), (iii), and (iv), §85.515(b)(10)(iii)(B), (C), and (D), or §85.520(b)(6)(iii)(B), (C), and (D), as applicable.

(d) This subpart specifies certain reporting requirements. We may ask you to give us more information than we specify in this subpart to determine whether your vehicles/engines conform to the requirements of this subpart. We may ask you to give us less information or do less testing than we specify in this subpart.

(e) EPA may require converters to submit vehicles/engines for EPA testing under any of the three age based programs. Under §85.510 or §85.515, if a vehicle/engine is selected for confirmatory testing as part of the demonstration and notification process, the vehicle/engines must satisfy the applicable intermediate and full useful life standards using the appropriate deterioration factors to qualify for an exemption from the tampering prohibition. If an outside useful life vehicle/engine is selected for testing, the vehicle/engine must demonstrate that emissions are maintained or improved upon after conversion to qualify for an exemption from the tampering prohibition.

(f) If you have previously used small volume conversion manufacturer or qualified small volume test group/engine family procedures and you may exceed the volume thresholds using the sum described in §85.535(f) to determine small volume status in 40 CFR 86.1838-01, 40 CFR 86.098-14, and 40 CFR 86.096-24(e)(2) as appropriate, you must satisfy the requirements for conversion manufacturers who do not qualify for small volume exemptions or your exemption from tampering is no longer valid.

(g) An exemption from the prohibition on tampering applies to previously issued alternative fuel conversion certificates of conformity for the applicable conversion test group/engine family and/or evaporative/refueling family, as long as the conditions under which the certificate was issued remain unchanged, such as small volume manufacturer or qualified small volume test group/engine family status. Your exemption from tampering is valid only if the conversion is installed on the OEM test groups/engine families and/or evaporative emissions/refueling families listed on the certificate.

(h) The applicable useful life of a clean alternative fuel converted vehicle/engine shall end at the same time the OEM vehicle's/engine's original useful life ends.