Removal and Installation: Removal

WARNING: This page is about a different car, the 2003 Nissan Altima. However, it is still accessible from the selected car via links, so may be relevant.

Remove engine under cover, with power tool.
Disconnect the electrical connector of each heated oxygen sensor, and unhook the harness from the bracket and middle clamp on the cover.
Remove the heated oxygen sensors with Tool.

Fig 1: Removing Heated Oxygen Sensor
Courtesy of NISSAN MOTOR CO., U.S.A.
CAUTION:
- Be careful not to damage heated oxygen sensor.
- Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
Remove the lower exhaust manifold cover.
Remove the exhaust front tube. Refer to Removal and Installation .
Remove the upper exhaust manifold cover.
Loosen the nuts in the sequence shown, on the exhaust manifold and three way catalyst.

Fig 2: Exhaust Manifold Loosening Sequence

Courtesy of NISSAN MOTOR CO., U.S.A.

Remove the exhaust manifold and three way catalyst assembly and gasket. Discard the gasket.