Dont be paranoid. all you do with a scan gauge is plug it in (inside the car) and look and see where your kr is at. 0 is ideal. if you continue to be paranoid you will learn nothing. carefull and paranoid are to different things.
here is a scan gauge (for gm engine parameters...such as kr) AeroForce Tech Interceptor OBDC2 Scan Gauges: 3800 Performance