Throttle body position sensor
 

Well here's a new problem. Had to get a new TPS as the old one crumbled UN my hand undoing bolts for the fuel rail as had to get injectors cleaned.

Which clock position does it have to be on fitment?

using the Perth-WRX mobile app

I think you mean tumbler valve position sensor.

You should not need to go anywhere near the TPS (throttle position sensor) when removing/replacing the fuel injectors.

From memory, there is a procedure to re calibrate it. Need a multimeter to set .5v and 0.
Youll need to push the prongs into the wires, adjust the sensor.
I could be thinking of something else tho.