Hi, I've had a remap done on my

Audi A2 1.4 TDI 2001 75bhp@ 100bhp

Something went wrong and after a week the car has stopped giving any boost and it has that distinctive sound of richer, deeper clogged exhaust instead of normal knocking.

MAFsensor shows normal under obd from 9- 70 or more g/s
but
MAP sensor is stuck at 90-94 kPa from the start and doesnt go anywhere (fried by linearisation map or something disconnected on the boost pipe?)

but before you judge in the MAP sensor linearisation map there are some changes like from 989 mV at 2600 mbar in original file

to 989 mV at at 2344 mbar

They havent changed the MAP sensor, so my next question is Do you only change linearisation when you change MAP sensor or you change it to cheat ECU to think it has more-less air to use on original MAP sensor.

The reason I also ask because somebody said that you can only change one part on this engine and you can go up to 120bhp. Would that be the MAP sensor and they put the right map for new one but forgot to change it?

ok, the deep sound was obviously the pipe disconnected from egr.

The question about MAP sensor linearisation map remained. Is it useful only when you change the sensor for bigger one or it helps to tune the remap somehow.

You should only change MAP sensor linearisation map when you put a different sensor.

There are some "original" files floating around with such a nasty mod done to them.
If you're asking for reason for such a sabotage, IDK.