starting and cutting problems help

hay all my dt4 is giving me a hard time dont know whats wrong struggle to start then goes fine for a few km
then mil comes on can feel loss of power through turbo then a few km later cuts out.if switch off for few seconds while going then on again fault goes away for few kms but gets worse after a few times then cuts out no starting after about 20 min starts again did do diagnostics but shown no error or code even with mil light on.

jobs done so far
drained all oil
replace all filters,clean tank mounted pump,cleaned pressure sensor and cam sensor,bypassed egr and cleaned intake manifold also cleaned hhp pressure regalator
any advice please?

When you say all filters, have you done the diesel filter???
What year is the car. Mine was doing similar and the water drain needed to be emptied and the diesel filter replaced and problem went away.

did replace diesel filter still same