has the fault cleared since you have changed the injector??
The covers on these engines used to be good at cutting through the injector wires.
That said even if you had one injector not firing it would start on three cylinders. if you unplugged the shorted injector.
essentially, you are; if you still have the original fault code looking at three things, injector, wiring, ECU.
you have changed the injector,you said you have checked the wiring if you still have the same code you need to check the supply and the signal to the injector from the ECU and compare it to a good injector.
remember renault count the cylinders from the flywheel side.
this engine have lots of problems with injector back leak, high pressure pumps snapping shafts and engine timing issues. so plenty to go at.....