Hi Nigel,
Just wondering how you got on. I just re/joined recently. I had a faulty turbo earlier this year which presented itself as intermittant very poor performance (pretty much the same symptoms as yours)... and then later (quite a bit later) it started whistling which confirmed the turbo was shot. I believe the problem may have been there a while, slowly dropping on power.. but when the car had a new timing chain and fresh set of injectors the problem really made itself known (I guess with everything else running super efficiently the problem became more obvious). Im not sure what caused the turbo issue itself though. I personally have kept on top of the oil level and changes etc... not sure about the previous owner who put approx 40k miles on the car before I got my hands on it. OR it could have been dirt in the engine from when I had to remove the sump (long story), but I did fill the engine with fresh castrol edge 0-30, ran it for a day then flushed the oil out with new edge turbo diesel 0-30... The car did also have a replacement exhaust manifold 5-6 months before the turbo went.. so it could be anything... (ps - may car has a standard map etc)
Honda originally quoted me £2366 to supply (parts = £1500+vat) and fit a new turbo, but after some negotiation (another long story) with Honda UK, they agreed to drop the parts cost to £475+vat (I think!), and the labour cost would be calculated by the dealership. It turned out I needed another new exhaust manifold which was replaced at the same time under warranty, so I ended up not having to pay any labout costs - so total job cost was approx £460 - which Im perfectly happy with.
Its worth speaking to Honda UK before comitting to a 3rd party new replacement/refurbished part.