Have you checked your diverter valve or pcv? if not id highly recommend doing so. my diverter valve was torn to shreds and fell apart when i took it out, felt soooo sluggish and snail paced and when i changed the vavle hey presto couldnt tell you how many times it was improved, car pulls like a train now!
Yeeeeah, did the DV when i had my map done n did the pcv on tuesday. Replaced the seals and the 'u' shaped clips on the intercooler to hard pipe turbo pipe cos they looked like they were leaking. It had oily sludge on the engine under trey now running out of ideas on what else it could be.