I’m curious to hear some stories about bad or costly diagnostic work done in shops by professionals. It’s mainly for entertainment purposes.
While on this topic I’d also like to hear the thruth from other professionals as well. While I firmly think that everyone should own their mistakes and take responsibility of their actions it’s not always just bad mechanics.
I speak from experience when I say that more often than not the diagnostic work goes so that the service advisor takes the car in for 30 minutes to “check the codes, it has a misfire” or something like that. The other way to get bad diagnostic service is when the customer isn’t willing to pay for it. In both cases I try to make it clear to all the people involved that I only read the codes and here they are but there’s still multiple possibilities that may cause the problem.