(a) For Tier 2 and later Category 1 and Category 2 engines, manufacturers shall test production line engines in accordance with sampling procedures specified in §94.505 and the test procedures specified in §94.506. The production-line testing requirements of this part do not apply for other engines.

(b) Upon request, the Administrator may also allow manufacturers to conduct alternate production line testing programs for Category 1 and Category 2 engines, provided the Administrator determines that the alternate production line testing program provides equivalent assurance that the engines that are being produced conform to the provisions of this part. As part of this allowance or for other reasons, the Administrator may waive some or all of the requirements of this subpart.

(c) The requirements of this subpart apply with respect to all applicable standards and FELs of subpart A of this part, including the supplemental standards of §94.8(e).

(d) If you certify an engine family with carryover emission data, as described in §94.206(c), and these equivalent engine families consistently pass the production-line testing requirements over the preceding two-year period, you may ask for a reduced testing rate for further production-line testing for that family. The minimum testing rate is one engine per engine family. If we reduce your testing rate, we may limit our approval to any number of model years. In determining whether to approve your request, we may consider the number of engines that have failed the emission tests.

[64 FR 73331, Dec. 29, 1999, as amended at 67 FR 68341, Nov. 8, 2002; 68 FR 9787, Feb. 28, 2003]