Man, I used to roll my eyes at those fancy scanners too. Had a similar stubborn idle on a 7.3 Powerstroke that drove me nuts for weeks. Finally borrowed a buddy's Snap-on scanner and it pinpointed a failing injector control module in minutes. Never doubted the value of proper diagnostics after that.

The NTSB database is full of reports where 'minor' issues were the precursor to major incidents. This pattern repeats in healthcare and construction whenever efficiency gets prioritized over procedure. Holding the line on compliance is frankly the least we owe the people relying on these systems.