Hi there I hope someone can help me,

My 2003 focus 1.8 tdci 115 is going into limp mode at high revs when using the turbo. Sometimes it would feel like there is no power at all throughout the rev range, especially in low down gears, and other times it would have good enough power and go into limp mode at around 3400 revs.

Now the veins and actuator seem to be fine, I just got the turbo cartridge reconditioned and cleaned out all the crap out of the veins. We checked that the actuator and veins were working by having one person start the car while the other looks at the actuator, and the arm goes down as normal, although it looks like it gets a little bit stuck on the way down but only for half a second.

Tried disconnecting the maf, no difference.

Hoses have no splits and have all new jubilee clips and are connected properly.

There are never any warning lights, except for an abs light that comes on sometimes but obviously that must not be related?

I have no idea what's wrong

What else should I check?

TL;DR car going into limp mode, what else should I check when turbo actuator and maf sensor seem to be fine?