Sounds like a plan. While the head is off, you also have the opportunity to decarbonise the engine and it might be worth mentioning that to your specialist as a possibility. I did not get this done because I didn't consider it at the time.
Basically the history of this is that the JTS was Fiat's first direct injection engine, and it wasn't perfect in a few ways - your car is probably a later one, which were better, so be grateful for that at least. One is that the injectors get covered in crap and cease atomising the fuel properly, and another is that it builds up carbon deposits that reduce the power output (which is probably about 145hp anyway).
Finally, when I had mine done, I replaced the engine wiring loom as preventative maintenance. There are some known issues with this, but whether this is worth doing is debatable - worth a mention to a specialist though.
All this sounds like bad news but I generally like my JTS and consider the expenditure to have been well worth it.
Yes, mine is a very late 2004 build but didn't make it to a forecourt until March '06, where it had picked up full Ti dress and sold immediately at what I assume was a bargain price, since the 159 was probably Alfa's priority by then. I'm the third owner and I know the car has been looked after, full service history and only a few of the more common faults that I knew of when I bought the car (Drivers-side A/C control had a mind of its own for example, but I finally got round to fixing it today.) So I guess its bad timing on my part.
I said that it didn't feel down on power, but If the engine has been full of gunk and the injector problem already present from when I bought the car, I probably wouldn't have noticed.
I'll certainly look into engine decarbonization and possibly a new engine wiring loom. I know Italian electronics are infamously poor, so I will look into that.
And if I can take up just a tiny bit more of your time, I've got an issue with the remote central locking where I can lock the car and open the boot with the key fob, but I can't unlock the car with the fob, a signal is sent because the lights flash and the alarm is de-activated, but I have to physically insert the key-blade to unlock the car.
Have you ever come across this issue? I've already started another threat on it but it seems a fairly rare problem, and hours of trawling the net have proved fruitless, so no solution yet.
Thanks again for all of your help,