Diagnostic Method 1

Detect the malfunction by checking "Cumulative value of time when λ changes from lean → rich" in comparison to "Time during which diagnosis is in progress".

Fig 1: Sensor Output Graph

Courtesy of SUBARU OF AMERICA, INC.

Judge as NG when the following conditions are established.

JUDGMENT VALUE

Malfunction Criteria	Threshold Value	DTC
(Cumulative value of time when λ changes from lean → rich)/(Time during which diagnosis is in progress)	< 0.39	P014C and P014E
	> 0.61	P014D and P014F

Time Needed for Diagnosis: 90000 ms

Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.