do they get dirty and need cleaning up? thats the red box on the side of the throttle body right?

my secs monitor reads 0% on idle, when i blip the throttle it increases in percentage then i let go and it drops back down to 0%

Also when i rev the car and let go of the accelerator pedal it bounces back up and it sounds like its getting a eletrical pulse or something coming through as the revs drop down to bounce back up. then it continues idleing abit hunty kinda thing. its not really bad hunting, but it does do it. Mate said its might be because of the high lift cams bd14 and bd10. But it can't be that cos it idles constant when the idle control valve is disconnected.

cheeRS