Diagnostic Method

WARNING: This page is about a different car, the 2022 Subaru WRX. However, it is still accessible from the selected car via links, so may be relevant.

Detect a malfunction by measuring the time from fuel cut completed until the rear oxygen sensor voltage begins to rise.

Courtesy of SUBARU OF AMERICA, INC.

Judge as NG when the following conditions are established.

JUDGMENT VALUE SPECIFICATION

Malfunction Criteria

Threshold Value

Output voltage value of rear oxygen sensor

Less than 0.2 V

Elapsed time⁽¹⁾

More than value of Map

⁽¹⁾	The time since the λ became less than 1 after the end of fuel cut

MAP SPECIFICATION

Average value of intake air amount (g/s (oz/s))	24 (0.85)	25 (0.88)	45 (1.6)
Elapsed time(s)	4.32	4.30	4.30

Time needed for diagnosis: Less than 1 s

Malfunction indicator light illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.