CFR /  Title 40  /  Part 91  /  Sec. 91.510 Compliance with criteria for production line testing.

(a) A failed engine is one whose final deteriorated test results pursuant to Sec. 91.509(c), for HC + NOX exceeds the applicable Family Emission Limit (FEL).

(b) An engine family may be determined to be in noncompliance, if at any time throughout the model year, the CumSum statistic, Ci, for HC+NOX. is greater than the action limit, H, for two consecutive tests.