Further developments... Took a chance and drove it 1/2 mile down the road once it had warmed up. CAr is only boosting to mechanical boost of 0.4bar. Not sure if a faulty MAF would cause this or if I have some other unknown issue. Was also making an unusual whooshing noise as I opened the throttle. Doh! No sign of an air leak but they can be a b***er to find...
