My gut feeling beat the scanner on a tough Duramax case last week

I get laughed at when I say this, but listening to the engine can tell you more than any code reader. Last week, a Duramax came in with a rough idle and no clear faults on the screen. Everyone reached for their laptops, but I just crawled under and listened. There was a faint ticking from the fuel rail that the computer missed. I tightened a loose fitting, and it purred like new. The guys thought I was nuts, but that truck drove out without a single part replaced. We spend so much on fancy tools that we forget the basics. Sometimes, the old ways are still the best.