[Joenavy85]

your engine will not run hot enough to ever benefit from water injection, don't waste your time. i agree with previous posts stating that you need to learn how these systems work before you start modifying them. EGR recircs INERT exhaust gases back to the intake, inert exhaust displaces the amount of combustible matter in the cylinder. Water injection was used in WW2 fighter aircraft to prevent premature detonation of the F/A mixture due to high operating temperatures, they still use it modern day on racing aircraft at the Reno air races, those aircraft engines are typically V12 engine with around 1500 cubic inches and around 4000HP with manifold pressures as high as 120 inches (ie, 44 pounds of boost) so unless that is what you are running it will likely do you no good. if it does do anything it will likely cool your intake charge and increase the humidity which will likely cause incomplete combustion, which can result in gas vapor in your exhaust which will slowly destroy your cats which you will then have to replace, negating any money you saved with increased fuel economy that was never really there