should my rs turbo cut out when the oil cap is removed??
any advice i am grateful for, cheers

yeh. Its cause the vacuum pressure has dropped.

I would say yes but could be wrong...

when they don't I think that indicates issues.

ahh rite, the air intake is plumbed into the breather or something isnt it?
thanks for that, i thought i had a problem somewhere lol

If you have Mfi with aftermarket oil seperator which vents to atmosphere it won't make a difference when you remove cap as feed to metering unit willbe blocked.
If you run standard breather set up to metering unit then it should cut or dip down when you remove cap as it creates a leak.

Yes, as the engine is now breathing through the oil cap, which is allowing unmetered air to bypass the airflow meter.

Rick