A-Premium Downstream O2 Oxygen Sensor for Nissan & Infiniti — 4-wire Heated Threaded Fit (Single)

The A-Premium downstream heated O2 oxygen sensor is a direct-replacement threaded sensor designed to restore accurate exhaust oxygen readings for compatible Nissan and Infiniti V6/V8 engines.

If your vehicle’s check engine light points to an oxygen-sensor issue or you want to ensure the downstream sensor is giving correct data to the engine control unit, this A-Premium unit matches OEM fitment for many Nissan and Infiniti models from the early-to-mid 2000s. It’s a four-wire, heated, threaded sensor supplied individually in a box and intended for downstream positions (left/right/front/rear depending on application). The sensor connects using a male electrical connector and arrives backed by a one-year unlimited-mileage A-Premium guarantee.

Which Nissan and Infiniti vehicles will this oxygen sensor fit?

This sensor covers numerous V6 and V8 models across Nissan and Infiniti for downstream locations. Fitment includes Altima, 350Z, Maxima, Quest, and multiple Infiniti G, FX, M, Q, and M45 model years as listed below. Always verify the OEM reference numbers and your vehicle’s model year and engine before ordering.

• Nissan Altima 2005–2006 V6 3.5L; 350Z 2003–2006 V6 3.5L
• Nissan Maxima 2004–2007 V6 3.5L; Quest 2004–2009 V6 3.5L
• Infiniti FX35/FX45/G35/M35/M45/Q45 model years covering 2002–2010 ranges per individual fitment

What are the technical specifications and reference numbers I should check?

This A-Premium downstream sensor is a four-wire heated design with threaded mounting and a male connector, shipped one sensor per box. Cross-reference the listed part numbers with your vehicle’s current sensor to ensure compatibility.

• Wire quantity: 4; sensor type: heated; mounting: threaded
• Connector: male; package quantity: 1 oxygen sensor in a box
• Reference numbers: 250-24403, 25024403, 250-24448, 25024448, 226A08J010, 226A1AR210, 226A1-8U700, 226A18U700

How will replacing the downstream O2 sensor help my vehicle perform?

The downstream sensor monitors catalytic converter efficiency and provides feedback used by the engine control system and emissions diagnostics. Replacing a failing downstream sensor restores accurate post-catalyst readings, which helps the ECU precisely interpret exhaust conditions and avoids false diagnostic trouble codes.

• Restores correct exhaust oxygen data to the vehicle’s computer
• Reduces chance of recurring check engine light from sensor-related codes
• Helps maintain proper emissions system monitoring and diagnostics

How do I install this A-Premium downstream oxygen sensor and what should I watch for?

Installation is straightforward for anyone comfortable with basic under-vehicle work: locate the downstream sensor on the exhaust after the catalytic converter, disconnect the factory connector, unthread the old sensor, and torque in the new one. Use anti-seize where recommended, check wiring routing and connector engagement, and clear codes after replacement to confirm the repair.

• Install in downstream positions: left, right, front, or rear depending on vehicle
• Use proper O2 sensor socket and torque to manufacturer spec
• Inspect harness and connector for corrosion or damage before finalizing

Who is this for: The A-Premium downstream O2 oxygen sensor is ideal for DIY mechanics and professional technicians servicing compatible Nissan and Infiniti models from the 2002–2010 era who need an exact-fit heated, four-wire threaded replacement. It’s suited for owners addressing emissions-related codes, replacing a failed downstream sensor, or restoring the exhaust monitoring system to proper operation—especially when matching reference numbers or replacing a worn OEM sensor. A-Premium’s one-year unlimited-mileage guarantee offers added confidence for routine repairs and emissions troubleshooting.