Seafoam Spray is for internal engine use only to clean carbon deposits from the intake systems, intake valves, and combustion chambers of your engine. It is a petroleum-based product designed for use in cleaning harmful gums, varnishes, and carbon from air induction systems and combustion chambers on all 2-cycle and 4-cycle gasoline engines. It cures hesitation, stalls, pings, flat spots, and rough idle due to carbon buildup. Seafoam Spray will clean intake valves and pistons, catalytic converters, and oxygen sensors, and will help restore power and pickup.