On Board Diagnosis Logic
WARNING: This page is about a different car, the 2004 Nissan Sentra. However, it is still accessible from the selected car via links, so may be relevant.
To judge the malfunction, the diagnosis checks that the heated oxygen sensor 1 output is not inordinately high.
Courtesy of NISSAN MOTOR CO., U.S.A.
Courtesy of NISSAN MOTOR CO., U.S.A.