Bank 1/Sensor 1

Switch "OFF" the ignition and disconnect the negative (-) battery terminal.
Disconnect the connector (A), and then remove the sensor (B).
Heated oxygen sensor:

39.2 - 49.1 N.m (4.0 - 5.0 kgf.m, 28.9 - 36.2 lb.ft)

Courtesy of KIA MOTORS AMERICA, INC.

Courtesy of KIA MOTORS AMERICA, INC.