Rear Heated Oxygen Sensor

Disconnect the battery negative (-) terminal.
Disconnect the HO2S connector (A).

Courtesy of KIA MOTORS AMERICA, INC.
Remove the connector (A) from the bracket in the arrow direction.

Courtesy of KIA MOTORS AMERICA, INC.
Remove the rear HO2S (A) after separating the wiring from the wiring fixing clip (B).
Tightening torque:

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

Courtesy of KIA MOTORS AMERICA, INC.