I'm not familiar with the "Octavia Sport" as a model designation either; UK models I'd expect to be Classic, Ambiante, Elegance, vRS and "Lauren and Klemens". A 1.9l TDi does suggest a VVT, but which engine tune is it; 90, 110 or 130bhp?

See attached link for spec of 2005 release of Octavia Sport. This is a 140 hp 2 litre PD engine but the name could have been used in the previous year on the 110 hp engine. Scroll down the page to find the spec.

Skoda Octavia Sport 2.0 TDI PD 5dr : Read reviews and compare prices at Ciao.co.uk

Link refers to an Octy A5 with 2.0l 140 and 6-speed or DSG.

Well I haven't rebuilt a turbo on the 2.0, but it's the same turbo so no reason why it won't suffer the same issues.

I'd recomend getting it tested first, a graph of requested vs actual boost and a visual inspection during a n75 output test cycle, followed by a full fault scan print out. Anyone who knows what they are doing should be able to have this done and emailed to you in about 15 minutes. If there is doubt about the actuator after the tests, vacuum can be tested during the output test to check the control system, also the actuator it's self can have vacuum applied via a vacuum pump and any leak measured. I do this first to be pretty confident the fault is in the VNT. Having said that, it always has been...

Greg.