VPS FUEL RAIL CLEANER is designed for professional use only. Detergents and cleaner added to the fuel tank may require up to three or four hundred miles of driving to remove troublesome deposits. VPS FUEL RAIL CLEANER allows professionals to remove deposits quickly and then diagnose any mechanical failures if fuel related problems persist after cleaning. VPS FUEL RAIL CLEANER contains powerful synthetic cleaners to clean fuel injectors immediately and removes deposits from intake valves and combustion chambers. These powerful synthetic cleaners are injected directly into the fuel system without being diluted with gasoline like cleaners added to the fuel tank. Valvoline Carb & Throttle Body Cleaner is a premium formula which contains a blend of effective cleaners to help restore engine efficiency and reduce gasoline consumption by quickly dissolving gum, varnish, sludge, grease, dirt and carbon deposits from carburetor throats, chokes and PCV valves. This fast action formula also quickly removes deposits from throttle plates and its sealing area. Its quick penetrating formula will clean hard to reach clogged passages and surfaces. Meets current low VOC regulations. Safe for oxygen sensors and catalytic converters. Equipment coated with gum, varnish, carbon or dirt becomes sticky and inefficient. Sluggish chokes and throttle linkages increase fuel usage and harmful emissions. Deposits coating the inside of a throttle body can cause rough idling, hesitation and surging. Sticky PCV valves can cause excessive oil consumption. Valvoline Carb & Throttle Body Cleaner safely removes these deposits without using harmful chlorinated solvents. With the engine off, disconnect the air duct from the throttle body. Spray the throttle plate and inside throttle body with Valvoline Carb & Throttle Body Cleaner. Open throttle plate and clean sealing area. Wipe dry with a soft cloth. Reattach air duct. For large open areas, simply hold can upright 4-6 inches from part to be cleaned and spray.