The spray from the Toyota fuel injector is what provides the combustible mixture of gasoline and air to each of the cylinders in your engine. Each fuel injector has to be fed with the cleanest possible source of fuel so they can function as they were designed to by the Toyota engineers. To help keep the interior of each Toyota fuel injector as clean as possible, several periodic maintenance procedures should be conducted by the owner of the vehicle. This has to include the changing of the fuel filter on a regular basis along with the placing of fuel injector cleaner in the fuel tank on every 10 fill-ups. This injector cleaner is the only way possible for the inside of the fuel injector to be cleaned of any residue that might build up. This is a fuel component that cannot be torn apart and cleaned. The outside can be cleaned up with solvent and a brush, but not the interior section of it. If this is not done and the injector becomes clogged, the atomized spray of fuel it was designed to introduce to each cylinder on your Toyota will not occur. Once a fuel injector has become clogged and only a dribble of fuel in emanating from the nozzle, it will have to be replaced. This is the only way to restore the fuel supply to your engine in a fashion that it was designed to receive. Until this repair procedure is carried out, the performance and mileage your Toyota engine will be producing will be less than its maximum potential. Because of this it is best to take very good care of your fuel system if you wish to drive your vehicle with the power you remember when it was new.