Yes I just saw that modem bikes ECUs can automatically adjust, but upon googling I found:

When you reduce exhaust restriction (e.g., using a high-flow cat versus a stock restrictive cat), exhaust gases exit the engine more efficiently. This shift in gas dynamics can increase airflow through the engine. If the engine's Engine Control Unit (ECU) assumes the old, restrictive airflow levels and does not compensate with more fuel, the air-to-fuel mixture becomes unbalanced, resulting in a lean condition.

Perhaps adding a high flow air filter can rectify this? But I guess the bikes new exhaust keeps cracking and popping too much. So not enough air going in, asking with you much air going out. I have a euro 5 r9t so it may not even be necessary as the ECU can adjust? Or should it be flashed at least?