O2 Oxygen Sensor Upstream Downstream for Infiniti QX80 (2016-2019) 5.6L

Direct-Fit Upstream & Downstream O2 Sensor Kit for 2016-2019 Infiniti QX80 (Z62)

What it Does: This 4-piece O2 sensor kit monitors pre- and post-catalyst exhaust on the Z62 Infiniti QX80 VK56VD 5.6L V8, regulating closed-loop fuel trim.

The Stock Infiniti QX80 Oxygen Sensor Failure

Factory sensors on the Z62 with the VK56VD 5.6L V8 endure severe thermal cycling, exhaust soot, and condensation. Over time, internal zirconia elements develop micro-fractures from heat soak while heater circuits suffer high resistance or open-circuit burnout. Oil blow-by and fuel deposits simultaneously foul the porous platinum electrodes. This sluggish voltage switching triggers fuel-trim faults like P0171/P0174, heater codes, and converter DTCs such as P0420/P0430.

Common Symptoms of a Failing OEM Oxygen Sensor

• Check Engine Light / DTCs: Triggers slow-response or catalyst codes including P0130/P0150, P2A00/P2A03, and P0420/P0430.
• Rough Idle & Hesitation: Corrupted upstream signals force erratic closed-loop fuel corrections or limp fueling.
• Poor MPG & Emissions Failure: Over-rich fueling fouls plugs and fails state emissions tests.

The Direct-Fit 4-Sensor Oxygen Sensor Solution

Replacing all four sensors simultaneously restores balanced bank-to-bank air-fuel metering across the VK56VD 5.6L V8. Each unit features a fast-acting planar zirconia element inside a laser-welded stainless housing with louvered shields that resist thermal shock. OEM-length heat-resistant harnesses and factory-style weatherproof connectors deliver clean signal transmission without splicing. Replacing OEM parts 234-9148, 234-8020, and 234-8021, these sensors thread directly into stock bungs.

What's Included

• 2 x Upstream Air-Fuel Oxygen Sensors
• 2 x Downstream Oxygen Sensors

Technical Specifications

Compatibility

• 2016 Infiniti QX80 5.6L V8 (Z62; pre-August 1, 2015 builds may differ)
• 2017-2019 Infiniti QX80 5.6L V8 (Z62)

Frequently Asked Questions & Fitment Warnings

Does this fit the Z62 QX80?

Yes. Direct fit for 2016-2019 Infiniti QX80 VK56VD 5.6L V8 models. 2016 builds before August 1, 2015 may require a different set; confirm engine before ordering.

Will this clear P0130 or P0420/P0430 codes?

Yes, when sensor-induced. New units resolve P0130/P0150 and P2A00/P2A03 faults; persistent P0420/P0430 codes require checking catalyst condition.

Is wiring splicing or hardware needed?

No. OEM-style plugs match 234-9148, 234-8020, and 234-8021—apply anti-seize to threads only.

The Infiniti Heavy-Duty Standard

Built for Z62 towing and thermal durability, this matched 4-sensor kit stabilizes closed-loop calibration. Accurate feedback protects converters and keeps the VK56VD 5.6L V8 running cleanly.