Corsa b 1999 x10xe engine one fault code reading map sensor replaced 3 times still the fault code returns and the engine stalls at every junction idle control and egr valve replaced no joy what else?

VSS Vehicle speed sensor? Its either ontop of the gear box or behind the speedclock on the rev counter. Try that. if you press both dash bottons on the lcd display whilst driving the display should come up with a speed reading which should be similar to the speedo dial, if it differs try replacing that VSS