On the test drive and drive home (about 10 miles) was perfect, was then parked up for about 2-3 weeks and since then it is massively down on power.
Started investigating and the air filter was soaking wet and bits of it had gone into the turbo, took the turbo off removed the bits of air filter and cleaned the turbo out, the blades on the turbo don't appear bent as when it's running it looks fine and doesn't make a racket, have also changed the fuel filter and had the fault codes read and nothing came up.
Anybody ever had a similar problem?