Prolong Super Lubricants PSL16122 Fast Fuel - Diesel Injector Cleaner - 12-Ounce Bottle is expertly formulated to thoroughly clean injector tips and intake valves. It is designed to remove carbon deposit clogs that can cause both misfiring and poor fuel economy. Periodic treatment can restore an uninhibited spray pattern that allows for the optimum firing rate that is essential for smooth and efficient operation.