2. Check For Short To Ground In Harness

1. Turn ignition switch to OFF position and disconnect HO2S and ECM connector.
2. Measure resistance between terminals 1 and 2 of the HO2S.
3. Measure resistance between terminal 2 of the HO2S and chassis ground.
   Fig 1: Measuring HO2S Harness For Short To Ground

   Courtesy of HYUNDAI MOTOR CO.
   • Specifications: infinite 

Does each resistance indicate open? 

Yes: Go to next step.

No: Repair short or short to chassis ground in harness.