O2 Sensor Inspection

■ HO2 Sensor Inspection 

1. Ignition "OFF"
2. Connect VMI to GDS and set up an oscilloscope as follow (2-channel);

   Channel A (+): Pin No. 1 (Signal) terminal of Upstream O2 Sensor.

   Channel A (-): Ground

   Channel B (+): Pin No. 1 (Signal) terminal of Downstream O2 Sensor.

   Channel B (-): Ground

3. Ignition "ON" & Engine "ON"
   Fig 1: Scantool Display - Upstream O2 Sensor And Downstream O2 Sensor Signal Waveform (Warm-Up Condition)

   Courtesy of KIA MOTORS AMERICA, INC.
4. Is measured value within specification?

   YES 

   • Go to "FUEL SYSTEM INSPECTION " procedure.
   • Carefully redo this troubleshooting guide steps.

   NO 

   • If the diagnostics have been performed correctly with no failure found, replace the downstream O2 Sensor and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.
     CAUTION:

     • Install the component with the specified torques.
     • Note that internal damage may occur when the component is dropped or mis-treated.
     CAUTION:

     • DO NOT use a cleaner, spray, or grease to sensing element and connector of the sensor because oil component in them may cause malfunction or affects on sensor performance.
     • Sensor and its wiring may be damaged in case of contacting with the exhaust system (Exhaust Manifold, Catalytic Converter, and others).