Ok idk if this s5 injectors need to be in the s4 turbo motor. Can this mess up my ecu? The car has all 4 s5 injectors idk why they would put those for, and they also put a s5 turbo. whats the difference between the injectors of a s4 and s5 turbo motors?

 

i heard all the T2 motors used 550cc injectors so they all should be the same. I think the only difference may be the connector type. I know the S4 used the primative clip style injector connectors that like to crumble once they get older like they did on my 86. They could have changed that in S5 since the pic you show looks to have a more rounded connector socket

 

Difference are low-impedance or high-impedance, read here: FC3S Pro v2.0: Mods - Fuel Injectors