A-Premium Downstream O2 Oxygen Sensor for Nissan & Infiniti — 4-Wire Heated, 400mm Lead, Direct-Fit

The A-Premium downstream O2 oxygen sensor is a direct-fit, 4-wire heated replacement designed to restore accurate exhaust oxygen readings for compatible Nissan and Infiniti models.

This replacement oxygen sensor (reference 250-241255) is built to match factory fit and function for downstream positions on a range of Nissan and Infiniti vehicles. It uses a threaded mounting, a female connector, and a 400 mm overall lead with four wires to integrate with the vehicle’s emissions and engine-management systems. The sensor ships in a protective box and includes a one-year unlimited-mileage warranty from A-Premium for added confidence.

Which vehicles does this A-Premium oxygen sensor fit?

This sensor covers a broad set of Nissan and Infiniti models in downstream (post-catalytic) locations. Check the engine code and model year before purchase to confirm compatibility.

• Nissan Altima: 2019–2021 L4 2.0L (B1S2, KR20DDET) and 2022–2024 L4 2.0L/2.5L.
• Nissan Kicks: 2018–2021 L4 1.6L (B1S2, HR16DE) and 2022–2024 L4 1.6L.
• Nissan Sentra: 2020–2024 L4 2.0L; Versa/Versa Note: various 2018–2024 L4 1.6L applications (B1S2, HR16DE).
• INFINITI QX50/QX55: select 2019–2024 L4 2.0L downstream positions.
• Nissan Pathfinder, TITAN and TITAN XD: specific downstream locations and sides as noted — verify vehicle engine and position.

How does this sensor’s design affect installation and compatibility?

The sensor uses a standard threaded mount and a female connector designed to match OEM electrical interfaces, which simplifies replacement. The 400 mm cable length gives suitable reach for common downstream mounting locations without excess slack.

• Threaded mounting for direct bolt-in replacement.
• Female connector matches factory harnesses on listed vehicles.
• 400 mm overall length accommodates typical downstream positions.
• Four-wire heated design for faster warm-up and stable readings.

What performance and specification details should I know?

This is a heated oxygen sensor with four conductors that provides the downstream (post-catalytic converter) oxygen signal to the engine control module. It’s designed to meet the functional needs of emissions monitoring and closed-loop fuel management on compatible vehicles.

• Reference number: 250-241255 (also listed as 250241255).
• Wire quantity: 4; Sensor type: heated oxygen sensor (HO2S).
• Connector gender: female; Mount: threaded; Overall length: 400 mm.
• Packaged individually in a box; package quantity: 1 sensor.

What warranty and quality assurances does A-Premium provide?

A-Premium backs this oxygen sensor with a one-year unlimited-mileage guarantee, aiming to give peace of mind for fit and function. The warranty covers defects in materials and workmanship under normal use according to the terms provided.

• One-year unlimited-mileage warranty from A-Premium.
• Shipped in protective packaging to prevent transit damage.
• Engineered for aftermarket fitment to match original electrical and mounting specifications.

Who is this for: This A-Premium downstream oxygen sensor is intended for vehicle owners, DIY mechanics, and professional technicians who need a reliable replacement sensor for the downstream (post-catalyst) position on supported Nissan and Infiniti models. Confirm vehicle year, engine code, and the sensor position (downstream/front/rear/left/right as applicable) before ordering to ensure correct fitment.