LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Subaru >> 2005 >> Baja Base, Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Diagnostic Trouble Code (DTC) Detecting Criteria (H4SO) >> Diagnostic Trouble Code (DTC) Detecting Criteria >> DTC P0139 - O Sensor Circuit Slow Response (Bank 1 Sensor 2) - >> Diagnostic Method >> Notes
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Method: Notes

When the oxygen sensor output voltage changes 0.5 V (rich) to 0.15 V (lean), calculate the Min. value of response time regarded as judgment value while the output varies from 0.45 V to 0.3 V.

Fig 1: Oxygen Sensor Output Voltage Driving Cycle (1 Of 2)
G03750018Courtesy of SUBARU OF AMERICA, INC.


When the oxygen sensor output voltage changes 0.15 V (lean) to 0.5 V (rich), calculate the Min. value of response time regarded as judgment value while the output varies from 0.3 V to 0.5 V.

Fig 1: Oxygen Sensor Output Voltage Driving Cycle (2 Of 2)
G03750019Courtesy of SUBARU OF AMERICA, INC.