Signal Circuit Inspection

IG "OFF".
Disconnect HO2S (B1/S1) connector.
IG "ON" & ENG "OFF".
Measure voltage between terminal 2 of HO2S (B1/S1) and chassis ground.
1. Specification : Approx. 0.45V
  
  Fig 1: Measuring Voltage Between Terminal 2 Of HO2S (B1/S1) And Chassis Ground
  Courtesy of KIA MOTORS AMERICA, INC.
Is the measured voltage within specification?
YES
1. Go to "GROUND CIRCUIT INSPECTION " procedure.
NO
1. Repair or replace as necessary and then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.