New OEM Nissan Upstream (Front) Oxygen Sensor for all '03 - '04 Nissan 350Z's and Infiniti G35's / FX35's.

2005+ Front oxygen sensors can be found HERE.

Installed before the catalytic converters on the exhaust manifold, these sensors often prove to be extremely difficult to remove without destoying the threads when installing an aftermarket set of headers or forced induction setup.  These sensors are also referred to as an "Air-Fuel Ratio Sensor" by Nissan.

Sold individually, one sensor will fit either the Left or Right side of the vehicle.

Z1 Motorsports recommends the usage of an anti-seize compound on the threads of the oxygen sensor to make future servicing much easier.

Please note: Late 2004+ G35 Coupe / 350Z models were equipped with wideband Front O2 Sensors. if your G has these sensors (indicated by black 6 pin connectors), please select 2005 as your year.