Amrxuts Oxygen Sensor Set for Subaru & Saab 2.5L H4 — 2-piece upstream + downstream, direct-fit tested

Amrxuts 2-piece oxygen sensor set (234-9123 upstream + 234-4445 downstream) replaces factory sensors on select Subaru and Saab 2.5L H4 models to restore accurate O2 readings and stable engine management.

If your check engine light points to an O2 sensor fault or your vehicle is running inefficiently after long service intervals, this matched upstream and downstream package gives you two direct-fit replacements engineered for plug-and-play installation. These aftermarket sensors are new, tested before shipping, and specified for Subaru Impreza (2006–2011), Legacy (2006–2009), Forester (2006–2010), Outback (2006–2009) and Saab 9-2X 2.5L H4 applications that use part numbers like 22641-AA36A and 22690-AA810.

How will these sensors affect my vehicle’s performance?

Replacing a failing oxygen sensor helps the engine control unit receive correct air/fuel ratio information so it can adjust fuel delivery and ignition timing more accurately. While results vary by vehicle condition, installing proper O2 sensors commonly leads to more consistent idling and smoother throttle response.

• Restores accurate oxygen readings for ECU adjustments
• Can reduce incomplete combustion and rough idle
• Helps the engine run closer to factory fuel trims

Are these Amrxuts sensors easy to install?

Yes — both sensors are designed as direct-fit aftermarket replacements that plug into the existing vehicle harness without modification. Basic hand tools and a suitable oxygen sensor socket are typically all you need, and each sensor comes with a four-conductor pigtail and factory-style connector.

• Direct-fit connector for OEM harness compatibility
• Upstream wiring: 19.69 inches, four conductors
• Downstream wiring: 20.87 inches, four conductors

Which vehicles and part numbers do these replace?

This pair is mapped to Subaru and Saab models using the listed OEM equivalents. The listing includes common cross-reference numbers so you can confirm fitment against your vehicle’s existing sensor stamping or service manual before ordering.

• Upstream replacements: 234-9123, 22641-AA36A and related cross-references
• Downstream replacements: 234-4445, 22690-AA810 and listed equivalents
• Fits Subaru Impreza, Legacy, Forester, Outback and Saab 9-2X 2.5L H4

What build quality and warranty can I expect?

These sensors are new aftermarket parts that undergo a 100% pre-shipment test for electrical stability and durability. The seller provides a one-year warranty period to address manufacturing defects or early-life failures under normal use.

• Brand-new aftermarket units tested before shipping
• Constructed for long service life and stable readings
• One-year replacement guarantee for qualifying quality issues

Who is this for: This Amrxuts two-piece oxygen sensor set is aimed at DIY mechanics, independent shops, and owners of the listed Subaru and Saab models who need reliable upstream and downstream replacements without modifying the factory wiring. Confirm OEM cross-reference numbers and model years before purchase to ensure correct fitment; ideal when your vehicle displays O2-related codes or when sensors reach typical service life.