Development Hydrogen-Fueled Internal Combustion Engine and Emission analysis .The use of hydrogen hydroxyl (Hydrogen-Hydrogen-Oxygen) gas as a fuel additive in gasoline for SI engines has a favorable impact on enhancing performance and decreasing the repercussions of burning fossil fuels alone. In this study, the effect of injecting HHO gas additive into the gasoline fuel of a gasoline engine was thoroughly investigated in order to increase overall efficiency by percentage 20% . The engine was connected to an electric generator to create electricity at a minimal cost. An experimental setup was developed to assess the performance indicators. The Hydrogen-Hydrogen-Oxygen gas was produced and injected into the intake manifold of the engine while it was running under various load situations. The essential parameters, such as engine RPM and electric generator output voltage/amperes, were measured, and performance indicators were calculated to assess the system's overall efficiency. The results showed that the Hydrogen-Hydrogen-Oxygen additive improved the performance of the gasoline engine more clearly when the gasoline content was lower in the air-fuel mixture