I don't have a boost gauge on it so I have no idea what kind of boost it's making, nor have I had any problems with it. As far as your 3 psi drop goes, who knows without getting into it. could be a leaky boost line to the gauge, detecting detonation, on and on. I would assume that if the clutch was slipping it would trip a code, but then again maybe not..........As you can tell I'm not an expert on these units and seeing as how I haven't had to troubleshoot mine for any problems my knowledge level remains low.