BG GDI Intake Valve Cleaner removes sticky, heavy deposits from the backs of valves and in air intake systems of Gasoline Direct Injection engines (GDI). Cleaning GDI intake valves requires a potent formula applied with proper equipment, due to both the placement of the injector inside the combustion chamber and the complexity of the intake design. Sprayed directly into the intake, BG GDI Intake Valve Cleaner restores fuel efficiency and engine performance, and reduces harmful exhaust emissions. Also effective for port fuel injection engines. Catalytic converter and oxygen sensor safe.