Hi
Try the below for starters:
Accelerator pedal value (max 100%)
Current throttle valve angle (max is 80% i think)
Lambda nominal value bank 1 and 2 (voltage)
Motor or engine speed (rpm)
Ignition point cyl 1
Intake air temp
Air mass measured
Pressure in front of throttle valve
Target boost pressure
Wastegate 1 pwm
Lamda values times by 14.7 to get AFR
Subtract ambient pressure of 850 from 'pressure infront of throttle valve'
For fuel related issues can also log below
Fuel low pressure sensor ( hpa)
Rail pressure (hpa)
Basically you need to monitor values related to what you suspect could be wrong.
Good luck