got a feeling the ICV and the knock sensor plugs are the wrong way round on my car
If they were I would be surprised if the engine would run.
The ECU sends out a high freqency to the ISCV to allow it open up more or close. However the knock sensor only has a 12v input, the rest is GND and an output to the ECU.
So if these were mixed up, the knock sensor would not have a 12v supply but a frequency (ie it would be powered) and the ISCV would have a constant 12v source (ie the valve would be almost closed and you would never be able to accelerate).
The plugs on my astra were crossed for 3 years!!!!!!!!!!. Itran fine, passed mots etc, just ticked over at about 1200 rpm. The engine management light was on constantly (but not till u hit 3000 rpm). The plug 4 the knock sensor is red on mine, but mines a 20xe . Just cross them .