INFINITI QX80 Oxygen Sensor Guide (2014-2024)
Understanding when and how to replace the oxygen sensors in your QX80's 5.6L V8 engine to maintain performance and fuel economy.
- Your QX80 has four O2 sensors; confirm the exact location (Bank 1/2, upstream/downstream) before buying.
- A check engine light with codes P0420, P0430, P0138, or P0158 strongly suggests an O2 sensor issue.
- For best results, choose OEM-equivalent brands like Denso or NGK/NTK for your INFINITI.
- Ignoring a bad O2 sensor can lead to poor fuel economy and eventual damage to the catalytic converters.
Is Your QX80 Oxygen Sensor Failing?
A bad oxygen sensor is a common reason for the check engine light to come on in your INFINITI QX80. When a sensor fails, the engine's computer receives incorrect data, which can lead to poor engine performance and increased emissions. Ignoring a failing sensor can eventually cause damage to your expensive catalytic converters.
Key Symptoms of a Bad O2 Sensor:
🎬 Watch this video to see common symptoms of a bad sensor.- Check Engine Light: This is the most common sign. Codes like P0420, P0430, P0138, or P0158 🎬 Learn how to address P0420 and P0430 codes on your Infiniti. often point to an O2 sensor issue.
- Worse Gas Mileage: A faulty sensor can cause the engine to run too rich (too much fuel), wasting gas.
- Rough Idle and Poor Performance: You might notice your engine running unevenly, hesitating, or misfiring.
- Rotten Egg Smell: A rich-running engine can produce a sulfur-like smell from the exhaust.
- Failed Emissions Test: Incorrect air-fuel mixture leads to higher pollution levels, which can cause you to fail a smog check.
Known Issues & TSBs
For 2018 QX80 models, INFINITI issued Technical Service Bulletin (TSB) ITB18-031. This TSB addresses an issue where the check engine light may come on with DTC codes P0138 or P0158 (Heated Oxygen Sensor 2 Circuit High Voltage for Bank 1 and Bank 2) without any actual drivability problems. The fix is a simple ECM reprogram performed by a dealer, not a sensor replacement. Always check if a TSB applies before replacing parts.
Choosing the Right Aftermarket Oxygen Sensor
When replacing an O2 sensor, you don't have to buy the expensive OEM part from the dealer. Quality aftermarket brands offer reliable performance, often at a much lower price. For Japanese vehicles like your INFINITI, certain brands are known for being original equipment suppliers, making them a top choice.
Brand Quality Tiers for Your QX80:
- Top Tier (OEM-Equivalent): Denso and NGK (NTK) are often the original equipment manufacturers for INFINITI. Choosing these brands is the closest you can get to the factory part's performance and longevity. They are highly recommended by mechanics for Japanese vehicles.
- Quality Aftermarket: Bosch invented the oxygen sensor and is a world-renowned supplier. While some mechanics prefer Denso/NGK for Japanese cars, Bosch direct-fit sensors are a reliable and widely available option. Delphi is another reputable brand offering quality replacement parts.
- Value-Oriented: Brands like Walker Products and DriveWire offer a more budget-friendly solution. These can be a good choice if you're looking to save money, but they may not have the same service life as top-tier brands.
Pro Tip: Upstream vs. Downstream Sensors
The upstream sensors (also called Air/Fuel Ratio sensors) and downstream sensors are not interchangeable. They have different functions and part numbers. Always verify the correct position (Bank 1/Bank 2, Upstream/Downstream) before ordering. Bank 1 is on the passenger's side of the engine, and Bank 2 is on the driver's side.
Cost of Replacing an INFINITI QX80 Oxygen Sensor
| Part Type | Price Range (Per Sensor) |
|---|---|
| New OEM | $190 - $387 |
| New Aftermarket | $53.43 - $325.79 |
| Shop Labor | $73 - $107 |
Frequently Asked Questions
How many oxygen sensors does my 2014-2024 QX80 have?
Your QX80 has four oxygen sensors. There is one upstream (before the catalytic converter) and one downstream (after the catalytic converter) on each side of the V8 engine (Bank 1 and Bank 2).
Should I replace all four sensors at once?
It is not required, but it is often recommended. O2 sensors wear out over time, so if one has failed, the others may not be far behind. Replacing them in pairs (both upstream or both downstream) or all at once can save you from future repairs and ensure the engine management system is getting consistent readings from all sensors.
Can I replace the oxygen sensor myself? 🎬 Follow this step-by-step guide to replace your QX80 oxygen sensors.
Yes, this is a DIY-feasible job for someone with moderate mechanical skill. Accessing the sensors, especially on the driver's side (Bank 2), often requires removing the front wheel and a splash shield. You will need a special oxygen sensor socket to remove and install the sensor without damaging the wire. Sometimes the old sensor can be seized in the exhaust pipe, requiring penetrating oil or heat to remove.
What is the difference between an Air/Fuel Ratio Sensor and an Oxygen Sensor?
In your QX80, the upstream sensors are technically Air/Fuel Ratio (A/F) sensors. They are a more advanced, wideband type of oxygen sensor that provides more precise measurements to the ECM. The downstream sensors are traditional, narrow-band oxygen sensors. When shopping, you will see both terms used, but it's crucial to buy the correct sensor for the specific location (upstream or downstream).
Helpful Videos
Technical Specifications
OEM Part Numbers: 22693-1LA0C 22693-1PM0A 226A0-EN21A 226A0-4BB0A 22693-6RA0A 226A0-5CA0A
The 5.6L V8 engine uses four heated oxygen sensors. The upstream sensors are wideband Air/Fuel Ratio sensors, while the downstream sensors are narrow-band. Thread size is typically M18x1.5. A specialized 22mm oxygen sensor socket is required for removal and installation.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- INFINITI QX80:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Is Your QX80 Oxygen Sensor Failing?
- Key Symptoms of a Bad O2 Sensor:
- Known Issues & TSBs
- Choosing the Right Aftermarket Oxygen Sensor
- Brand Quality Tiers for Your QX80:
- Pro Tip: Upstream vs. Downstream Sensors
- Cost of Replacing an INFINITI QX80 Oxygen Sensor
- Frequently Asked Questions
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