Hi all. 2009 1.3cdti 43k from new and for the last 5 weeks has been smokey and spluttery on start up from cold. Until it warms up it is also knocky. When warm the smoke has gone and the car settles down. Got it plugged in as car and spanner light is now on and got the code P0400-61 EGR valve stuck. Is this problem causing the smoke and knocking problem at start up ? Have tried some Wynns and STP egr clearner sprays but no difference. Cheers