With that (expensive!) computer
The computer is cheap. Very cheap. You can often replace it yourself and have the dealer program it for you. It's dealers that charge too much for the computer (typically about $800). It's about the same cost as replacing a distributor.
Only a few are required to run the engine. They are all simple in their construction. They are all pretty easy to replace if needed.
as you've mentioned, and more things that can cause problems.
If a sensor fails, the computer knows which one and tells you. Replacing them is pretty trivial.
Many race cars are computer operated (Top Fuel cars have been for years). I'm not in denial of that. Hell, my Hyundai has bluetooth and I have it hooked up.
Okay.
My point is the electronic throttle downright sucks. It's ok on the highway, but in stop 'n' go traffic, there sometimes is a severe hesitation if you're on and off the throttle.
Not the thottle's fault. Nor is the fault of FADEC. You probably have bad plugs or boots. Sometimes a fault in the cam advance system can cause this.
Another thing that sucks is the cost of the diagnostic equipment, most small garages can't afford it
$20 for an ODB2 tester is pretty cheap. It will cover almost everything you need.
so you're stuck taking the car to a dealership that charges $100 right off to hook it up and $120 an hour labor to fix it.
Don't need it. I do all the maintenance on my own cars. They are all FADEC designs. I have yet to take it to a dealer for anything.
Pretty high price to pay when the "small" guy can fix it with the turn of a screw on a carburated engine.
You can do the same thing on a FADEC car. They are not that difficult to work on. Turning the screw on a carburetor is just guessing. It may not fix the problem and only result in a misadjusted carburetor. BTW, I work on a lot of carburetor engines, and even rebuild the carburetors. I know what I am doing and generally don't need to adjust anything on them.
I do, however, like the tire pressure sensors (when they don't get loaded with dirt and salt), maintaining proper tire pressure is very important.
The sensor is not exposed, so they shouldn't get loaded up with dirt or salt. The wheel tone sensor (used for traction control systems and cruise control systems) is also not exposed, and also shouldn't get loaded up with dirt or salt.
Should either sensor fail, they are easily replaced.
Heck, I've repaired backup collision sensors with nothing more than a bit of superglue.
Don't be discouraged by the FADEC design or modern car design. Yeah, it's different than that '57 Chevy, but it's not hard to learn it. All it really means is learning what each system does and what each sensor does. You take it one step at a time, like a mouse eating an elephant. That scary looking wire harness coming out of the computer is just a collection of circuits. Learn them one at a time. Almost half of them are ground wires!
There's a wire going to each cylinder to fire the plug.
There's a wire going to each cylinder to fire the injector.
There's two or three wires going to your accelerator pedal.
There's a wire going to your crankshaft position sensor.
There's a wire going to your camshaft position sensor.
There's about 3 or 4 wires going to your mass airflow sensor.
That's it. That's all the critical stuff the computer needs to run the engine.
Fuel supply is dead simple. A pump brings up fuel pressure to somewhere between 30psi and 60psi. That is fed to the fuel rail serving all the injectors. There is a small gasket (kind of like an O ring) where they connect.
Pressure is maintained by a simple spring, draining excess fuel back to the tank. The computer fires each injector at or near the the time the intake valve is opening. No more fuel wasted along the induction system plumbing through condensation of fuel vapors.
Even the pollution control crap is pretty simple. The EGR system is just a pipe from the exhaust to the induction system, with a valve to prevent reverse flow on the negative pressure cycle in the exhaust. By feeding exhaust gasses into the induction system, you reduce the peak burn temperature in the cylinder, and any NOx gasses generated by high temperatures. It is the most effective method of preventing smog, and is cheap to implement. No computer is involved here, other than perhaps cycling the valve.
The fuel vapor controls are pretty simple too. Fuel vapors in the induction system are stowed in a nearby canister filled with activated charcoal when the engine is shut off. Starting the engine again sucks these vapors back out and essentially primes the induction system with fuel ready for the engine. It keeps fuel vapors from getting out into the atmosphere and causing smog.
Smog is unburned fuel (fuel vapors), ozone (generated by the engine itself or by the exposure of oxygen to sunlight), and NOx gasses. Eliminate just one of these, and you have eliminated the smog.
