Diagnostic Method

Detect the trouble by calculating the response time of the rear oxygen sensor after fuel cut.

Fig 1: Rear Oxygen Sensor/Response Time Graph

Courtesy of SUBARU OF AMERICA, INC.

Judge as NG when the following conditions are established.

JUDGMENT VALUE SPECIFICATION

Malfunction Criteria	Threshold Value
Time needed for rear oxygen sensor voltage to change from 0.3 V to 0.5 V	> 4000 ms

Time Needed for Diagnosis: Less than 1 second

Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.