VALVOLINE PROFESSIONAL SERIES 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. VALVOLINE PROFESSIONAL SERIES FUEL RAIL CLEANER allows professionals to remove deposits quickly and then diagnose any mechanical failures if fuel related problems persist after cleaning. VALVOLINE PROFESSIONAL SERIES 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. VPS Express Smoke-Free Induction Cleaner cleans fuel system components that most fuel injector cleaners fail to reach without the exhaust smoke common after these services are performed. VPS Express Smoke-Free Induction Cleaner is professionally installed using an installation tool and works with VPS Fuel Injector Cleaner to thoroughly clean intake valves, manifold ports and combustion chambers. VPS Express Smoke-Free Induction Cleaner contains powerful cleaners to clean fuel induction systems and formulated to eliminate exhaust smoke.