i recently put the greddy 18g kit on my 00 si i already now not a great kit and could have done much better but to the point since i hav put it on water drips from the exhaust it doesnt lose coolant and and runs at normal temp dont know whay it does this

it's normal. Water is a by product from the cat doing it's job.

A perfect car engine's exhaust would have only 2 products: water and carbon dioxide (CO2). Since no motor is perfect it's those products plus a bunch of other crap that kills our environment, depleats the O-Zone layer, and creates smog. Do me a favor and plant a tree so it can filter all the crap that comes outta our cars. Aren't trees great!!!