i have a 2009 AVEO LT but it's not the american version, aparently this one is Korean, the other day i brought it to a shop to change the sparkplugs and after putting a new set of laser iridium NGK it started having problems, like a piston stopped working for a second and then worked again, it did that for a few days, i brought it back and apparently the cables were old, i got a new set and still was doing the same, the i checked it with an OBDII and it said the Air flow sensor had problems, it was not getting enough electricity, i brought it back to check the wiring going there, the mechanic disconnected all the cables and could not find it broken, he put it all back as it was and then the car would not start, he said it was the computer or ECU because he was not getting pulse on the injectors, after i almost killed him i bought a new ECU but now it wont turn on, i brought 3 guys to configure it but their machines say they cant access the ECU, what can i do?

my brother in law said get a piggy back controller or a stand alone for the injectors? where can i get one ?

this is the worse car i've ever had!!!