vauxall zafira 1.6 petrol.while driving if i go above 40mph and then need for whatever reason to slow down touch the break down gear then back on the gas the car starts to jerk so again i drop down gear the rev counter drops to 0 car stalls.this happens on b-roads and motorway.ive been told its egr valve and its common problem.can you help

gez, November 2010