Diagnostic Method 1
Detect the malfunction depending on the average value of time necessary for λ to inverse the air fuel ratio from "Lean → Rich → Lean" to "Rich → Lean → Rich".
Judge as NG when the following conditions are established.
JUDGMENT VALUE SPECIFICATION
| Malfunction Criteria | Threshold Value | DTC |
|---|---|---|
| Average value of time necessary for λ to inverse the air fuel ratio to Lean → Rich → Lean | > 80 ms | P015A |
| Average value when λ is lean | > 100 ms | |
| Average value of time necessary for λ to inverse the air fuel ratio to Rich → Lean → Rich | > 70 ms | P015B |
| Average value when λ is rich | > 110 ms |
Time needed for diagnosis: 90 seconds
Malfunction indicator light illumination: Illuminates as soon as a malfunction occurs.