WARNING: This page is about a different car, the 1989 Nissan Pickup and 1989 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Code 21 Pathfinder, Pickup (1 of 2) (4-Cylinder)
Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 2: Code 21 Pathfinder, Pickup (2 of 2) (4-Cylinder)