Toyota TTC stands for Toyota Total Clean System, a moniker used in Japan to identify vehicles built with emission control technology. The technology was installed so that their vehicles would be in compliance with Japanese Government emission regulations passed in 1968. The term was first introduced in Japan, with an externally mounted badge on the trunk of vehicles equipped. The technology first appeared in January 1975 on the Toyota Crown, the Toyota Corona Mark II, the Toyota Corona, the Toyota Carina, the Toyota Corolla, and the Toyota Sprinter. There were three different versions initially introduced, called TTC-C for Catalyst, installing a catalytic converter, TTC-V for Vortex, installing an exhaust gas recirculation valve, and TTC-L which used a lean burn method. As Toyota's technol