Egads, I take a 3 week Vacation and people resort to the worst way to fix a car.
There are test proceedures for EFI systems. If "your" mechanics can not properly test and diagnose these problems, got to someone else who can.
If you have a car that is FRYing injectors, replace all injectors, the ECM, and find the short that is causing them to die. Also on cars with Crank Triggers, if the Trigger(hall effect)goes bad too, you definatly are shorting. Just tossing parts at it and not finding the root cause is going to get expensive. Charles