300 less? I have the opposite
problem with over boost and high egr readings after new recon turbo. Could be that your maf needs cleaning. Buy some electrical contact cleaner and give the maf a little blast with it. Don't touch it though just let the cleaner do the work. I bought we 40 specialist quick drying contact cleaner. Made a massive difference. This was before my turbo though. These are my readings
Has also been suggested that actuator arm on turbo adjusted incorrectly but not sure that would be the case with you.