Noticed over the last couple of days, when accelerating esp from low revs, the revs would build quite jerkily and the boost would waver quite noticeably, but then go back to normal as the revs rose. Now today as i drove the car the problem got worse, to the point where there is virtually no boost at all. You can hear the turbo spool a tiny bit thru the intake at 2k revs but then after that no spool and no boost :-(. Pretty much the same thing happend before and was cured with a new diverter valve (revised metal piston D version) and then a new N75 valve, as the new DV valve was causing overboost. Just wondering has anyone had one of these piston type revision D valves fail, or have their N75 valve fail for a second time? Both parts have only been on since April, but have seen some hard use on this car. Is it worth me upgrading to a Forge diverter valve and a strengthened N75 spring while I'm at it? Also fitted my BSH PCV fix today, which was fairly straightforward, and noticed a fair bit of oil in the PCV hose that joins the intake manifold to the cylinder head, now with this fitted much less of this crud will be going back into my intake and I should gain 1-2 PSI of boost under load, however due to the boost problem above I can't test this out properly untill the valve/s are sorted. Any help appreciated.