O2 Oxygen Sensor Upstream Downstream for Volvo XC90 (2005-2011) 4.4L

Direct-Fit Upstream & Downstream O2 Oxygen Sensor Kit for 2005-2011 Volvo XC90 (P2)

What it Does: This 4-piece oxygen sensor kit restores closed-loop air-fuel ratio monitoring and catalyst diagnostics on the 2005-2011 Volvo XC90 P2 chassis with the B8444S 4.4L V8.

The Stock Volvo XC90 Sensor Degradation

On the P2 XC90 equipped with the B8444S 4.4L V8, factory sensors endure severe heat soak inside the tight V8 engine bay. Thermal cycling fatigues internal heater circuits while oil vapor and additives glaze the zirconia sensing element. This contamination slows voltage switching speed and skews fuel trims across both banks, triggering P0135, P0155, or catalyst efficiency codes like P0420 and P0430.

Common Symptoms of a Failing OEM Oxygen Sensor

• Check Engine Light / DTCs: Triggers P0130, P0135, P0150, or P0420/P0430 from heater faults or slow switching.
• Fuel Trim Skew & Rough Idle: Biased voltage feedback causes uneven idling and hesitation.
• High Fuel Consumption: Stuck enrichment increases fuel use and fails emissions.

The Direct-Fit Matched 4-Sensor Solution

Replacing all four sensors simultaneously eliminates cross-bank voltage lag between Bank 1 and Bank 2 on the B8444S V8. Each unit pairs a fast-light-off heater with a thermal-shock-resistant zirconia ceramic element and laser-welded stainless housing to block moisture ingress. Pre-terminated OEM-style harnesses route directly into the P2 exhaust manifolds and mid-pipes without cutting or splicing, matching OEM part numbers MHK500870 and 30774700.

What's Included

• 2 Upstream Oxygen Sensors
• 2 Downstream Oxygen Sensors

Technical Specifications

Compatibility

• 2005-2011 Volvo XC90 4.4L V8 (B8444S) — 4 sensors (2 upstream, 2 downstream)
• Excludes 2007-2014 XC90 3.2L models; confirm engine before ordering (Volvo S80 4.4L separate)

Frequently Asked Questions & Fitment Warnings

Does this fit the P2 XC90?

Yes. Fits 2005-2011 Volvo XC90 B8444S 4.4L V8 models. Does not fit 3.2L engines; confirm engine before ordering.

Will this clear P0135 or P0420 codes?

Yes, if faulty sensors are the cause. Replacing the matched MHK500870 / 30774700 set restores closed-loop feedback after verifying zero exhaust leaks.

Are all four sensors plug-and-play?

Yes. Includes 2 upstream and 2 downstream direct-fit sensors with OEM plugs—torque to spec without contaminating tips.

The Volvo Precision Standard

Engineered for accurate ECM closed-loop control, this matched kit restores factory fueling precision and CEL-free emissions compliance on your P2 XC90 V8.