I got the Lamda control bank errors again which last time was the DISA valve, so I knew there was a vacuum leak somewhere.
Under the bonnet this time I found that this thing was half out, pipe thing that connects to the air intake after the MAF sensor. (I must have disturbed it while sorting out the cooling system) :
I've fixed it back in and checked the pipes after the MAF sensor for any cracks/tears and there doesn't appear to be. I've also reset it on INPA.
My question is are the sensors that sensitive that this pipe being half out could bring up an error/rough idle or is there something I'm missing?
P.s. I've driven around for about 20 miles today and the light hasn't come back on, nor is it rough on idle.