CFR /  Title 40  /  Part 90  /  Sec. 90.710 Compliance with criteria for production line testing.

(a) A failed engine is one whose final deteriorated test results pursuant to Sec. 90.709(c), for HC+NOX (NMHC+NOX) or CO exceeds the applicable Family Emission Limit (FEL) or standard if no FEL.

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