Golf TDI 110cv loss of power...

I own a 1998 VW Golf TDI 110cv that as far as today has run 190.000 km. I have a problem with the engine, but I'm not sure what to check/replace. I'm experiencing a major loss of power, especially at high rpm (over 3.800 rpm), so that my maximum speeds doesn't exceed 180 km/h and I think that also 0-100 km/h acceleration has lost 1 or 2 seconds. In general my engine seems to be much less responsive.

What could be the problem, or what is the checklist for that kind of things?
Some friends of mine suggest to check the turbo and repair or replace it... but I would prefer to look somewhere else before, I think that replacing or repairing it would be extremely expensive.

Thank you for your help,
bye

Read all the post on your MAF sensor. It reads as if your MAF is in lag mod due to failure which is common on TDi's for many members here.

Here's a European solution that was posted as of recent.

MAF Pierburg.

arrivederci
M.D.

My MAF has been changed not so much time ago... I don't think that the problem is there... any other idea?

Thanks