vivaro engine management light on at speed over 60 mph?

Hi i have a vivaro 06 1.9 I have an engine man light that is doing my head in. The problem I have is when I go over 60 the man light comes on. I got a local garage to plug there TEC 2 in and they told me it was a MAS flow air sensor code and a high boost pressure so I brought a genuine vauxhall MAS flow and a boost pressure switch cleared codes and the light still comes on. I then swapped the EGR value with a vivaro with no light coming on but still light comes on. It is better but still comes on over 70 and when engine is under pressure up hills. The garage i use have drawn a blank said it could be turbo but as the van is running ok and turbo is working around town they don’t think this is the problem has anyone got any info that could help me the codes are po100 (B) mass air flow high input.
P1125 (1) boost pressure solenoid valve excessive flow detected
Help please