Idle/stalling problem VTS

[TSVTS]

I've had my vts for bout 7 months now and its always had a dodgy idle. Sometimes sitting at lights the revs drop to near stalling point but manage to pick up agaiin. Normal road speeds it pulls fine and accelerates like a mofo. I got a chance to get some diagnostics and live data stream last night and it came up with two faults, both of which mean 'F' all to me.

:Richness regulation autoadaptation short circuit to earth
&
: Knock sensor High limit.

Any ideas what all this means? I've havent stopped paying out on this car fixing stuff since i had it so need some help to solve this one.

[badasssaxo]

pretty much all saxo's have an idle problem at some point, there are many threads on this, but its and easy fix at no cost

the idle control valve needs either cleaning or replacing try cleaning it first b4 replacing it you will need carb cleaner for this, clean the trottle body too, if this doesnt work it may also be the map sensor,

try searching relevant threads for more answers too

[TSVTS]

Thanks for your info but Idle control valve and throttle body has all been dismantled and cleaned twice since i've owned it. TBH i dont think the previous owner understood about maintenance so have probably spent about £500 - £600 replacing just wear and tear parts. The car data was reading 496mb manifold pressure and 20 step at the stepper motor. Whatever that means?
Cheers