O2 Oxygen Sensor Upstream Downstream for Ford Expedition (2012-2014) 5.4L

Direct-Fit O2 Oxygen Sensor Kit for 2012-2014 Ford Expedition (U324)

What it Does: This 4-piece upstream and downstream oxygen sensor kit monitors exhaust oxygen on 2012-2014 Ford Expedition (U324) 5.4L 3V Triton V8 models to regulate fuel trims and catalyst efficiency.

The Stock Ford Expedition Sensor Failure

On the U324 equipped with the 5.4L 3V Triton V8, factory oxygen sensors suffer from extreme exhaust heat soak, thermal shock, and carbon fouling. Over time, the internal zirconia element degrades and the heater circuit burns out, triggering P0135, P0155, P0141, or P0161 codes. Sluggish voltage switching skews PCM fuel trims, causing rich mixtures, rough idling, and catalytic converter stress.

Common Symptoms of a Failing OEM Oxygen Sensor

• Check Engine Light / DTCs: Triggers heater and response codes including P0135, P0155, P0141, P0161, or P0171/P0174.
• Poor Fuel Economy: Delayed closed-loop feedback forces rich fuel maps, increasing consumption and carbon buildup.
• Emissions Failure: Unburned fuel overheats exhaust substrates, leading to P0420/P0430 catalyst efficiency faults.

The Direct-Fit Zirconia O2 Sensor Solution

This matched 4-piece kit replaces both Bank 1 and Bank 2 upstream and downstream sensors to restore factory closed-loop control. Each sensor features a laser-welded stainless housing and fast-acting zirconia ceramic element calibrated to 234-4576 specifications. Direct-fit weatherpack connectors eliminate splicing, ensuring clean voltage signals and durable resistance under heavy towing loads on the 5.4L 3V Triton V8.

What's Included

• 2 Upstream Oxygen Sensors
• 2 Downstream Oxygen Sensors

Technical Specifications

Compatibility

• 2012 Ford Expedition (5.4L V8)
• 2013 Ford Expedition (5.4L V8)
• 2014 Ford Expedition (5.4L V8)

Frequently Asked Questions & Fitment Warnings

Does this fit the U324 Expedition?

Yes. Direct fit for the 2012-2014 Ford Expedition 5.4L 3V Triton V8. Confirm engine before ordering; excludes 3.5L EcoBoost models.

Will this clear P0135, P0155, or fuel trim codes?

Yes, when caused by worn sensors or failed heaters. Replacing all four sensors restores closed-loop accuracy on the U324 PCM.

Are connectors included for plug-and-play installation?

Yes. Each sensor includes factory-style plugs matching 234-4576 for direct installation without cutting or splicing.

The Ford Heavy-Duty Standard

Built for sustained exhaust heat under heavy towing loads on your 5.4L 3V Triton V8. Restore accurate fuel metering and emissions reliability across all four positions.