Customer in Reno made me rethink my whole diagnostic approach

Guy brought in a clunky 2012 F-150, rough idle, throwing a P0301 code. I was ready to sell him plugs and coils, like I always do. He asked me to check the fuel trim data first, said his last mechanic in Phoenix caught a bad injector that way. Looked at the numbers, sure enough, bank 1 was running way lean. Swapped the injector, smooth as glass. Cost him $180 instead of $600. Made me realize I lean on codes too much and skip the live data. Anyone else guilty of that or am I the only one?

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thomas_martinez1mo ago

You ever had a customer teach you more than any training class? Same thing happened to me with a Chevy Silverado a couple years back. I kept chasing misfire codes on cylinder 6, threw parts at it for two days. Owner was a retired diesel mechanic, watched me do it, then asked if I'd checked the injector pulse width on the scanner. I hadn't. Ten minutes later, found a clogged injector that the computer never flagged. Now I pull up fuel trims and live data on every miss before I even look at parts. It's like reading the engine's mind before you cut into it. Saves everyone time and money, and honestly, it makes me look smarter than I am.