O2 Oxygen Sensor Upstream Downstream for Subaru Legacy Outback Tribeca (2010-2014) 3.6L

Direct-Fit Upstream & Downstream O2 Sensor Kit for 2010-2014 Subaru Legacy, Outback & Tribeca (BM/BR/WX)

What it Does: This 4-piece oxygen sensor kit monitors air-fuel ratios and catalyst efficiency on 2010-2014 Subaru Legacy, Outback, and Tribeca models with the EZ36D 3.6L engine.

The Stock Subaru Legacy, Outback & Tribeca Sensor Failure

Factory oxygen sensors on the BM/BR Legacy/Outback and WX Tribeca endure extreme thermal cycling along the EZ36D 3.6L exhaust manifolds. Heat soak and carbon soot foul the platinum electrodes, while moisture condensation fractures the zirconia element. Burned-out internal heater circuits delay closed-loop operation during cold starts. Degraded feedback skews fuel trims and triggers P0131, P0151, or P0420/P0430 fault codes.

Common Symptoms of Failing OEM Oxygen Sensors

• Check Engine Light / DTCs: Triggers fuel trim, heater, or catalyst codes including P0131, P0171, P0420, and P0430.
• Rough Idle & Hesitation: Sluggish closed-loop voltage switching causes erratic air-fuel mixtures and bogging under throttle.
• Poor MPG & Failed Emissions: Rich open-loop fueling fouls plugs and spikes tailpipe hydrocarbons.

The Direct-Fit Heated Zirconia Sensor Solution

This matched 4-piece kit replaces both bank upstream AFR sensors and downstream catalyst monitors on your EZ36D flat-six. Laser-welded stainless housings shield fast-acting internal heater cores and dual-layer zirconia elements from exhaust corrosion. Pre-terminated OEM connectors ensure clean electrical output and true plug-and-play installation into factory bungs without splicing. Replacing all four sensors simultaneously restores balanced bank-to-bank fuel control.

What's Included

• 2 Upstream Oxygen Sensors
• 2 Downstream Oxygen Sensors

Technical Specifications

Compatibility

• 2010-2014 Subaru Legacy 3.6L
• 2010-2014 Subaru Outback 3.6L
• 2010-2014 Subaru Tribeca 3.6L

Frequently Asked Questions & Fitment Warnings

Does this fit the BM/BR/WX Legacy, Outback, and Tribeca?

Yes. Fits 2010-2014 Legacy, Outback, and Tribeca models with the EZ36D 3.6L engine. Excludes 2.5L 4-cylinder trims; confirm engine before ordering.

Will this clear P0420/P0430 or heater circuit codes?

Yes, if sensor-induced. New sensors fix sluggish switching and heater faults (P0135/P0155); persistent P0420/P0430 codes indicate catalyst wear.

Are OEM-style connectors included for installation?

Yes. All sensors include direct-fit OEM connectors; apply anti-seize only to threads before torquing.

The Subaru Precision Standard

Replacing all four sensors restores ECM fuel-trim accuracy and CEL-free operation on your EZ36D. Built for thermal durability, this kit maintains emissions compliance and crisp throttle response.