The status of Toyota's development of low emission concept packages- 1.NOx and HC/CO Catalytic Converter and EGR, 2.Thermal Reactor, NOx and HC/CO Catalytic Converter and EGR and their components is described. Variations of thermal reactor design, performance and durability characteristics are discussed. Above the throttle valve entry EGR has been found to have desirable flow characteristics with a simple control system. EGR rate over 15% brings about unacceptably poor driveability and fuel economy with smaller vehicles. Many types of catalytic converters for pelleted catalysts have been designed and examined for their performance and durability. A down-flow type converter has relatively good flow distribution and warm-up characteristics. As for HC and CO, a few prototype vehicles have met the 1975 Federal Regulation at low mileage, but the 1976 regulation for NOx of 0.4 gm./mi. is very difficult to meet even with a significant penalty in driveability and economy for our smaller vehicles.