P0153 Hyundai

Question

new O2 sensor with no change.
The Sensor output curve looks well.
Can we asume that the a/f ratio works well?
Why the check engine light returns to appear?

Answer 1

P0153 H02S circuit slow response Bank 2 Sensor 1

The 02 sensor output will look well, is there is any exhaust leak prior to the 02 sensor this will set a P0153.

 Here a exhaust that set a P0153, the fix here was to seal the exhaust leak