Amrxuts Oxygen Sensor Set for Subaru 2.5L H4 — Upstream & Downstream 2‑Piece Direct‑Fit (2006–2011)

Amrxuts 2-piece upstream and downstream oxygen sensor set replaces part numbers 234-9123 and 234-4445 to restore proper exhaust sensing on 2006–2011 Subaru Impreza, 2006–2010 Forester/Legacy/Outback and 2006 Saab 9-2X 2.5L H4 vehicles.

This matched pair includes one upstream (pre-cat) and one downstream (post-cat) oxygen sensor engineered as direct-fit aftermarket replacements for the listed Subaru and Saab applications. Each sensor is fully tested before shipping and supplied with four-conductor wiring; harness lengths are approximately 19.69 inches for 234-9123 and 20.87 inches for 234-4445. The set targets reliable operation, corrosion-resistant durability and straightforward installation without modification.

Which vehicles and part numbers do these sensors fit?

These sensors are designed for 2.5L H4 Subaru and related Saab models from the mid-2000s. They match common OEM and aftermarket cross-references so you can verify fitment against your vehicle’s existing part numbers.

• Compatible models: Subaru Impreza (2006–2011), Outback (2006), Legacy (2006–2009), Forester (2006–2010), Saab 9-2X (2006).
• Cross-referenced part numbers: 234-9123, 234-4445, 22641-AA36A, 22690-AA810 and related OEM codes.
• Engine: 2.5L H4 applications only—confirm engine code before ordering.

How does installation work and what tools will I need?

These oxygen sensors are direct-fit replacements designed to install with the factory wiring harness and mounting points. Most jobs require basic hand tools and a sensor socket; anti-seize is typically applied to the threads during installation.

• Wiring: 4-conductor leads for each sensor; lengths ~19.69" and ~20.87".
• Tools: oxygen sensor socket, ratchet, penetrating oil, torque wrench recommended.
• Time: expect about 30–90 minutes depending on access and vehicle lift availability.

What performance and durability features should I expect?

These aftermarket sensors are built to address common wear and to offer long service life under exhaust system conditions. They are tested before shipment to ensure signal stability and connector integrity.

• Material: corrosion-resistant sensor housing and protective boot for the wiring junction.
• Function: restored oxygen sensing and feedback for the engine management system.
• Warranty: 1-year replacement guarantee for manufacturing defects when contacted by email.

Will these sensors clear a check engine light and improve fuel management?

Replacing faulty oxygen sensors can eliminate oxygen-sensor-related diagnostic trouble codes and restore accurate air–fuel feedback to the ECU. While individual vehicle results vary, installing functioning upstream and downstream sensors helps the engine control module make correct fueling adjustments.

• Addresses codes related to oxygen sensor performance when replacement is required.
• Supports smoother closed-loop fuel control by providing accurate exhaust composition readings.
• May improve fuel efficiency if poor sensor readings were causing rich or lean conditions.

Who is this for: Owners and independent mechanics who need direct-fit upstream and downstream oxygen sensors for mid-2000s Subaru 2.5L H4 models or the Saab 9-2X, and who want tested aftermarket parts with a one-year guarantee. Confirm engine type and OEM part cross-references before purchase to ensure compatibility.