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SKU:
NLT1I00872
Ships for free in 2–4 business days.
2006-2011 Subaru 2.5L Upstream and Downstream O2 Sensor Pair
$66.99
In Stock
$66.99
Sale price
$66.99
Regular price
This new aftermarket oxygen-sensor pair replaces 234-9123 upstream and 234-4445 downstream for compatible non-turbo Subaru 2.5L applications.
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Compatible Models
We do our best to list all compatible models. Although this may be the part you need, your exact model may not appear below.
Compatible equipment / model
- Subaru Forester 2.5L non-turbo (2006-2010)
- Subaru Impreza 2.5L non-turbo (2006-2011)
- Subaru Legacy 2.5L non-turbo (2006-2009)
- Subaru Outback 2.5L non-turbo (2006-2009)
- Saab 9-2X 2.5i (2006)
Product Overview
Poor fuel trim, slow sensor response, catalyst-monitor faults, or damaged wiring may call for one or both sensors after exhaust leaks, misfires, fuel delivery, and engine oil consumption are checked. The front sensor guides mixture control while the rear sensor monitors converter operation, so position matters.
Do not swap front and rear sensors. Subaru calibrations vary by engine, emissions package, and build date. Match connector, wire length, sensor position, and original number before ordering.
Key Features & Performance
- One upstream air-fuel / oxygen sensor and one downstream sensor
- Position-specific connectors and leads for matching applications
- Replaces damaged heaters, contaminated elements, or slow sensors
- Pair supports complete exhaust-sensor service
Replaces Part Numbers
- 234-9123 upstream
- 234-4445 downstream
- 22641-AA360
- 22641-AA36A
- 22690-AA810
- 22690-AA81A
Common Uses
- Replacing a failed sensor heater circuit
- Correcting a confirmed slow or biased sensor
- Repairing damaged sensor wiring after exhaust work
Technical Specifications
- Product Type: Upstream and downstream oxygen sensor set
- Engine: 2.5L non-turbo compatible applications
- Quantity: 2 sensors
- Condition: New aftermarket replacement
Installation & Fitment
- Identify front and rear positions before removal
- Repair exhaust leaks ahead of the sensors
- Route wires exactly away from heat and rotating parts
- Use anti-seize only if the threads are not pretreated
- Clear codes and review live data after repair
Compatibility Notice
Northline Parts does its best to list all known compatible models. The correct part may fit an application that is not shown above. Model year, production date, serial number, engine or equipment specification, installed options, and previous repairs can change fitment. Match the original part, reference number, dimensions, connectors, mounting points, and product photos before purchase.
Frequently Asked Questions
Q: Are the two sensors interchangeable? A: No. The upstream and downstream sensors perform different jobs and may have different connectors.
Q: Will replacing both fix P0420? A: Not automatically. Converter efficiency, exhaust leaks, fuel control, oil burning, and wiring must be diagnosed.
Q: Do these fit turbo models? A: The listed fitment targets non-turbo 2.5L applications; verify the original sensors.
Q: Is this an original-equipment part? A: No. This is a new aftermarket product. Brand names and part numbers are used only to identify compatible applications.
Part Summary
keywords: 234-9123 Subaru oxygen sensor, 234-4445 downstream O2 sensor, Subaru 2.5 oxygen sensor pair, Forester Impreza O2 replacement, Legacy Outback sensor kit
Brand names, model numbers, and reference part numbers are used for identification and compatibility purposes only. Verify the original component, specifications, and application before purchase.