Okay. It could be the ECU that is not firing the injector however, I would wonder what the electrical specialist did with the wiring. If there were melted wiring found that is where I would start. I understand they zip tied the connector back together but this is not a sufficient repair. If it were me not only would I want them to replace those connectors but they need to test resistance in all of those wires. I suspect there is a wiring issue for that injector and each of those other codes. I just wouldn't want to see them put a module in it and it still does not fix it. Unfortunately it happens too often.
If you want to "test" them. Ask "what the resistance measurement was for each of the wires for the injectors and those that were melted." Proper resistance should be measured in Ohms and be less than a half ohm for a single wire. If they say they were "good" I would press them to make sure they actually checked each one. If they haven't then I would do the module until that is done. Otherwise, you could be wasting your money on a module.
Let me know if you have questions. Thanks
Thursday, October 3rd, 2019 AT 7:56 PM