The sensors will need a tap on a spanner to get them to unscrew no doubt.
It sounds like the non-MF59 one and those Ecu's are pretty reliable. The MF59 type suffered from corrosion on the aluminium heat sink and some of the internal earth connections became high resistance.
MultiEcuScan shows the parameters/readings of things but is not cheap for the full setup. A garage would normally have the diagnostic equipment to read things but It's down to the person to interpret the readings to find a problem.