I've said for years that technology in vehicles was gettin too big for its britches. And even though I'm not a fan of EFI conversions on older cars, I love the modern conveniences it brings to new cars. When things are right, it's great. It's when things go haywire, as they often do, that stuff gets outta hand.
I don't know how it is in the areas where yall live, but here, it's impossible to find someone that 100% knows what they're doing with computer diagnosis. It always ends up being a "best guess" and that's bullshit.
Even all the dealerships around here have no one that "really knows" the systems. They all rely on communicating with the factory reps online and lots of times, they're wrong too.
Used to be with carburetors and distributors, it was "yeah Mrs. Jones, just park it right there and Mike will HAVE IT FIXED later this afternoon". Now, it's gotta jump through this hoop and that, plug this in, communicate with the factory rep, lick their nuts, slob their knob and you still might not get it fixed.
Dealers sometimes have problem children in for so long that they go through arbitration. That's the process where the dealership buys the POS BACK that you bought from them. That's just pitiful.