You have to be sure your system is set up according to instructions... engine damage will only be incurred if your fuel enrichment is not set up properly... the nitrous creates LOTSof extra oxygen in your engines combustion chamber and the fuel must be added to maintain a rich enough mixture so you don't melt down the pistons... do watch for nitrous lag... this occurrs after you let off of the funny button and the car still wants to get it on for another second or two.. it is a strange feeling at first.. good luck