Did anyone ever get to the bottom of these issues?

I've got a 2009 fiesta 1.6 tdci with the hdi engine. But seems to happen to alot to other engine sizes
I've not got any engine/warning lights or fault codes

I've replaced,, mass sensor, map sensor, air intake temperature sensor, egr, glow plugs, turbo, wastegate, vacuum pipes, dpf, quality oil and filter, fuel filter.

Its cost me a fortune and still goes into limp mode now and then.

Seems to happen more on higher revs or higher speed (private road test) of course.

Someone somewhere must know the answer to this problem