Maybe the sensor has 'MarijnReuvers' syndrome and it takes YEARS to respond...


MAP-sensor tends to overfuel when fucked so probably it's not that, no point measuring the sensor by itself: measure over the pins in the multiplug that connects to the ECU.

Boostgauge hose might have gone soft and could be leaking air so boost could actually be higher than 0.5 - 0.6 bar although you should feel it cutting the ignition when the boost spikes.

Mind you: airchargetemps will be VERY VERY HIGH as ambients are 35-ish...try on the motorway and see if it's get's significantly better when there's enough airflow over the IC.