Not his car.
I think voltage low means that the brown wire is shorted to ground
the red/blue wire is broken (check it's 12v with ignition on)
wrong plug plugged in? (idle valve/knock sensor plug?)
The wiring should come dirrectly out of the black plastic channel above the injectiors.
If the brown wire rearly is shorted to ground the valve will be perm open which will cause rough running at idle and minor throttle.
Turbo ones are different to NA ones as they are pressure sealed.