I will say though mate all cars will vary with different settings etc, Ok so when your up to temp mate and idle is steady, is the fpr then showing 3.4 bar? If so adjust it and drop it down to 3 bar, but like Colin said and I have asked still waiting for your answer mate here what is your afr readings on full boost, Do it in 3rd and 4th and see what readings your getting, Obviously on a good clear straight road