I have 2010 Petrol automatic.
Problems occur only when engine warm. Car does not start properly and cranks for several seconds before finally firing. When car in "Drive" it hunts / rocks when stationary. The ref counter drops to approx. 600rpm when in Drive and idling and this is when it hunts / rocks.
The car has already been checked for "fault codes" and none have shown so far. MAF and ECT checked, no problems found.
EGR has been checked and passed OK
Further observations:
• If engine is turned off and on immediately, it fires, even if hot. It needs to be left for approx. 20 minutes and then has problem starting.
• If engine is cold, e.g. Overnight, it fires ok
• The hunting problem is much worse when engine warm (i.e. No "choke")
This seems connected with idle speed which drops when in "Drive", which causes the hunting. If revs upped slightly then the hunting stops