O2 Oxygen Sensor Upstream Downstream for Ford F-250 F-350 (2006-2009) 5.4L 6.8L

Direct-Fit Oxygen Sensor Kit for 2006-2009 Ford F-250,F-350 (P131 / P356)

What it Does: Replaces all four upstream and downstream oxygen sensors on 2006-2009 Ford F-250,F-350 5.4L V8 and 6.8L V10 trucks to restore closed-loop fueling.

The Stock Ford F-250,F-350 Sensor Failure

On P131 / P356 Super Duty trucks with the 5.4L 3V Triton V8 or 6.8L 3V Triton V10, OEM oxygen sensors suffer exhaust heat soak, moisture intrusion, and carbon fouling. Thermal cycling fractures the zirconia substrate and burns out internal heater circuits, triggering P0135, P0141, P0155, and P0161 codes. Sluggish voltage switching skews fuel trims, causing P0171/P0174 lean faults and false P0420 catalyst codes.

Common Symptoms of a Failing OEM Oxygen Sensor

• Check Engine Light / DTCs: Triggers P0135, P0141, or P0420 from burnt heaters or slow switching.
• Fuel Trim Hesitation: Stale upstream voltage causes rough idle and P0171/P0174 lean faults.
• Emissions Failure: Forces rich open-loop fueling and failed inspections.

The Direct-Fit Stainless Oxygen Sensors Solution

This matched 4-piece kit supplies two upstream and two downstream sensors built for P131 / P356 exhaust geometry. Stainless housings, laser-welded shields, and fast-light-off zirconia elements resist thermal shock during heavy towing. Factory-style Weather-Pack plugs and pre-coated threads bolt straight in, directly replacing OEM numbers 234-4045, 234-4374, and 234-4127 without harness splicing.

What's Included

• 2 Upstream Oxygen Sensors
• 2 Downstream Oxygen Sensors

Technical Specifications

Compatibility

• 2006-2009 Ford F-250 Super Duty (5.4L V8 / 6.8L V10, 4-Sensor Layout)
• 2006-2009 Ford F-350 Super Duty (5.4L V8 / 6.8L V10, 4-Sensor Layout)

Frequently Asked Questions & Fitment Warnings

Does this fit the P131 / P356 F-250,F-350?

Yes. Direct fit for 2006-2009 Ford F-250,F-350 with the 5.4L 3V Triton V8 or 6.8L 3V Triton V10. Excludes 2000-2005 models and 2-sensor federal-emissions trucks; confirm emissions configuration before ordering.

Will this clear P0135, P0141, or P0420 codes?

Yes, when sensor-induced. New heaters and zirconia elements clear P0135, P0141, and P0420 sensor faults unless the catalyst is damaged.

Are connectors ready for plug-and-play installation?

Yes. Direct-fit plugs match 234-4045, 234-4374, and 234-4127; torque into clean bungs.

The Ford Heavy-Duty Standard

Built for towing thermal loads on the P131 / P356 platform, this kit restores closed-loop fueling accuracy and ensures CEL-free operation.