[SilverDales]

Hi, well that didn't work. I have a W reg Corsa diesel 1.7 Izuzu engine. It has been holding back and hunting at 55/60 mph 3000 revs. This has been getting a little worse steadily and is now happening around 50 mph and when I try to go uop hill.
I have tried cleaning the EGR valve to no avail and then ordered a blanking plate and fitted that this morning. Also to no avail.
Can anyone help me here please?