I have a few questions about this thing the system already installed on the car only the nozzle is not. before i fit the nozzle do I need to clean the intake manifold? because from what I see methanol "cleans" the intake and I don't want some old stuck dirt to get to the engine am I right? what about this mixture of 70% water 30% methanol its not flammable in case of leak? and if I inject only water does it make damage to the engine ?