----- 2.5.4 Exemption Programs 42 2.6 Enhanced Compliance Oversight as a Result of Volkswagen Clean Air Act Violations 44 3. Light-Duty Vehicles 47 3.1 Certification 47 3.2 Production Volume 48 3.3 Confirmatory Testing 51 3.4 Fuel Economy Testing 51 3.5 Durability Testing 52 3.6 In-Use Compliance Testing 52 3.7 Defect Reporting 58 3.8 Recall Reporting 62 3.9 Averaging, Banking, and Trading ...