Front Heated Oxygen Sensor

Disconnect the negative (-) battery terminal.
Disconnect the connectors.
A : Rear heated oxygen sensor connector

B : Oil pressure sensor connector

C : Front heated oxygen sensor connector

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

Courtesy of KIA MOTORS AMERICA, INC.
Remove the front heated oxygen sensor (A) by using the SST (09392 - 1Y100 or 09392-2H100).
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.