Touran 1.6S rough cold start & suddenly low MPG

[Cass IoW]

My 2006 1.6S touranEngine type BSE has started playing up when started from cold and I have noticed the average fuel consumtion(for the same journey and traffic conditions) has dropped from 36-38mpg down to the high twenties. The symptoms at coldstart is the engine runs rough and starts hunting up and down with a lot of smoke black/grey. also occasionally there is a smell of petrol. I guess the same symptom as having the choke pulled out too far in the old days.
I have also noticed a clunking/ knocking noise has apeared from the N/S front when the steering is turned It sounds almost like a dry rubber bush. but I guess thats for another thread. The VW main dealer on the Isle of Wight is hopeless but there is a good independant, but I would like to have some idea of what it might be.

[VAGMAN54]

could be as simple as a coolant temp sensor but a scan would give you a fault code for an idea of where to go first as guessing will be expensive ,an air leak would also cause an overfuelling issue ,a sticking egr valve would cause poor starting and a smell of fuel so i woild say get it code read first then we can go from there.......

[Cass IoW]

Ive started looking at the emmision control system and today stripped out the crankcase breather pipe and the pipe between the filter and inlet manifold. There was a lot of emulsified oil scum in the oil filler and the hose from the rocker cover to the inlet just before the throttle butterfly. Where the hose meets the main intake there apears to be a small red valve, the diaphram seems to have swelled or distorted because of the oil etc. Can these be replaced? It looks like it can but it is not listed in the parts lists I have. Next step is removing the butterfly unit and EGR valve to check if its clean. We are going to hook it up to the PC and scan it tommorrow.