STP Complete Fuel System Cleaner is a professional-grade fuel additive engineered to restore optimal engine performance. This 18 oz. formula dissolves fuel injector deposits, cleans intake valves, and removes carbon buildup throughout your fuel system. By restoring fuel flow efficiency, it enhances combustion, improves fuel economy, and reduces emissions. Ideal for vehicles experiencing rough idling, hesitation, or reduced power. Simply add to your fuel tank—no special tools required. Trust STP's proven technology to keep your engine running at peak efficiency.