A-Premium Downstream O2 Oxygen Sensor for Nissan & Infiniti — Single 4-Wire Heated

The A-Premium Downstream O2 Oxygen Sensor is a direct-fit, heated 4-wire replacement sensor designed to restore accurate post-catalyst oxygen readings on select Nissan and Infiniti V6/V8 models.

This aftermarket downstream (post-catalytic) oxygen sensor from A-Premium is engineered to match OE fitment and electrical specifications for a range of Nissan and Infiniti vehicles from the early to late 2000s. It measures residual oxygen in exhaust gases after the catalytic converter so the engine control unit can fine-tune fuel trim and emissions strategies. Sold as a single threaded sensor with a male connector, it arrives in protective box packaging and includes a one-year unlimited-mileage warranty from A-Premium.

Which vehicles will this A-Premium downstream O2 sensor fit?

This sensor is designed for specific Nissan and Infiniti platforms—check the exact model years and engine sizes before ordering. It supports both left/right and front/rear downstream positions depending on the vehicle application.

• Nissan Altima (2005–2006) V6 3.5L; 350Z (2003–2006) V6 3.5L
• Infiniti FX35 (2003–2006) V6 3.5L; FX45 (2003–2008) V8 4.5L
• Infiniti G35 (2003–2006) V6 3.5L; M35 (2006) V6 3.5L; M45 (2003–2004, 2006–2010) V8 4.5L
• Nissan Maxima (2004–2007) V6 3.5L; Quest (2004–2009) V6 3.5L; Q45 (2002–2006) V8 4.5L

How does this downstream sensor compare to the original equipment part?

The A-Premium sensor mirrors the OE configuration with a heated element and a threaded mount for straightforward bolt-in replacement. It uses a four-wire harness and a male connector to match the factory electrical interface, which simplifies installation and helps preserve signal integrity.

• Heated sensor design for quicker operation at low temperatures
• 4-wire configuration for heater power and accurate signal return
• Threaded mounting to match factory exhaust ports and gaskets
• Male connector keyed to OE wiring harnesses for plug-and-play fit

What technical details and reference numbers should I check before buying?

Verify part references and connector style against your vehicle’s existing sensor. A-Premium lists multiple equivalent reference numbers to help cross-reference with OE and aftermarket catalogs.

• Reference numbers: 250-24403, 25024403, 250-24448, 25024448
• Additional codes: 226A08J010, 226A1AR210, 226A1-8U700, 226A18U700
• Specification summary: 4 wires, heated sensor, threaded mount, male connector
• Sold as: 1x oxygen sensor in boxed packaging

What warranty and support does A-Premium provide?

A-Premium includes a one-year, unlimited-mileage guarantee covering manufacturing defects, giving you replacement or refund options if the sensor fails under normal use during that period. Customer support resources and fitment guides are available to assist with selection and installation questions.

• One-year unlimited-mileage warranty
• Boxed packaging for protection in transit
• Customer support for fitment and installation inquiries

Who is this for: The A-Premium Downstream O2 Oxygen Sensor is aimed at owners and technicians working on compatible Nissan and Infiniti models who need a cost-effective, OE-style downstream replacement. If you’re restoring exhaust system performance, troubleshooting a downstream oxygen sensor code, or replacing a failed heater circuit, this direct-fit 4-wire sensor offers straightforward installation and an A-Premium warranty for peace of mind.