When deleting the DEF | Urea | SCR | AdBlue system on an AGCO machine like Challenger, Valtra, Massey Ferguson, Deutz and so on with the Bosch EDC17CV54 ECU and SISU engine it is necessary to disconnect the DEF | Urea | SCR | AdBlue quality sensor.
If this sensor stays connected the machine might derate periodically.

You can see the disconnected sensors plug in the photo below.