CAA MOBILE SOURCE CASE - THE CASE CONCERNS THE SALE OF AUTOMOTIVE PARTS AND COMPONENTS THAT RENDER INOPERATIVE EMISSION CONTROL SYSTEMS ON EPA-CERTIFIED MOTOR VEHICLES AND MOTOR VEHICLE ENGINES (DEFEAT DEVICES) IN 7 INSTANCES BETWEEN APRIL 25, 2017 and December 19, 2020. THE EPA HAS DETERMINED THAT THESE ACTS ARE IN VIOLATION OF TITLE II OF THE CLEAN AIR ACT (CAA) 203(a)(3), 42 U.S.C. 7522(a)(3). THE VIOLATIONS INCLUDE THE SALE OR OFFERING FOR SALE OF: (i) ENGINE CONTROL MODULE REPROGRAMMERS (ALSO KNOWN AS TUNERS ) THAT DISABLE EMISSION CONTROL SYSTEMS AND/OR DISABLES DIAGNOSTIC TROUBLE CODES (DTCS) ON EPA-CERTIFIED MOTOR VEHICLES, SUCH AS EXHAUST GAS RECIRCULATION (EGR) SYSTEMS, VEHICLE ENGINE ACTIVE FUEL MANAGEMENT, ON-BOARD DIAGNOSTIC SYSTEMS, REAR OXYGEN SENSORS, AND/OR DIESEL PARTICULATE FILTER (DPF) SYSTEMS.