Circuit Insulation Check

Disconnect connector from HO2 sensor.
Using ohmmeter, check circuit insulation of HO2S sensor. If faulty is found, replace HO2S sensor.
- Between each heater terminal (1) and other than heater terminals (2).
  
  Fig 1: Checking Resistance Between HO2S Heater Terminals No. 1 & 2
  Courtesy of SUZUKI OF AMERICA CORP.
- Between each terminal ((1), (2), (3) and (4)) of HO2S sensor and HO2S sensor body (5).
  
  Fig 2: Checking Resistance Between Terminals Of HO2S Sensor & HO2S Sensor Body
  Courtesy of SUZUKI OF AMERICA CORP.
Connect HO2S sensor connector securely.