$ diff <(cut -d, -f1,2 old_output.csv | sort) <(cut -d, -f1,2 new_output.csv | sort)
1c1
< A1001,163
---
> A1001,162
9c9
< A1009,361
---
> A1009,360
11c11
< A1011,113
---
> A1011,112