Parts for your 2020 Nissan Pathfinder-Oxygen sensor

2020 Nissan Pathfinder oxygen sensor — what it does and when to replace it

Technical sources confirm the 2020 Nissan Pathfinder does use oxygen-sensor hardware. Nissan’s Factory Service Manual for the R52 (2020), Engine Control (EC) section and wiring diagrams, show two front air–fuel ratio sensors (Bank 1 Sensor 1 and Bank 2 Sensor 1) and two rear heated oxygen sensors (Sensor 2) for the 3.5‑litre V6. Nissan parts catalogues (e.g., 22693‑xxxxx for A/F sensors and 226A0‑xxxxx for HO2S) and major aftermarket catalogues from NGK/NTK and Bosch list these sensors for this model. This layout is required to meet OBD‑II/ADR emissions monitoring.

On the 2020 Pathfinder, the front air–fuel ratio sensors constantly report how rich or lean the exhaust is so the engine computer can trim fuel and keep things running smoothly and efficiently. The rear oxygen sensors sit after the catalytic converters and check that the cats are doing their job. Together they help deliver good fuel economy, tidy emissions, and crisp driveability.

They’re largely “fit and forget”, but they work in brutal heat and eventually slow down or fail. Common signs owners might notice include:

• Check engine light with codes like P0131–P0161 or P0420
• Heavier fuel use (higher L/100 km), hesitant throttle, or rough idle
• Failed emissions/WOF/roadworthy due to catalyst efficiency

As part of regular servicing, workshops usually inspect wiring and connectors, check for exhaust leaks, and scan fuel trims and sensor switching speed. Cleaning isn’t recommended, contamination from silicone sprays, coolant or oil shortens sensor life. Many techs suggest testing and replacing only the failed unit, but on higher‑kilometre vehicles (say 160,000–200,000 km) it’s sensible to consider both upstream sensors together if data shows they’re getting lazy.

Replacement tips a good workshop will follow:

• Confirm faults with live data and smoke/pressure tests for exhaust leaks before fitting parts
• Use the correct type: wideband A/F sensors for the front, narrowband HO2S for the rear
• Allow the exhaust to cool, use an O2-sensor socket, don’t twist the loom
• Most quality sensors come with anti‑seize on the threads, avoid contaminating the tip
• Tighten to the service‑manual spec and perform a drive cycle to set readiness monitors

Looked after this way, the Pathfinder’s oxygen-sensor setup helps the V6 run sweet, save petrol, and keep the catalytic converters happy — which keeps the rego inspections hassle‑free.

How many oxygen sensors are on a 2020 Nissan Pathfinder?

It has four in total: two front air–fuel ratio (wideband) sensors, one on each bank before the catalytic converters, and two rear heated oxygen (narrowband) sensors after the converters. This arrangement lets the ECU control mixture precisely and verify catalyst performance.

Can it be driven with a bad oxygen sensor?

Usually yes for a short stint, but it’s not ideal. Expect heavier fuel use, sooty emissions, and the risk of damaging the catalytic converters if it runs rich for long. It may also trigger a failed WOF/roadworthy. Best bet is to diagnose and sort it promptly.

Are the upstream and downstream sensors interchangeable?

No. Upstream units are wideband air–fuel ratio sensors with different internals, response, and connectors. Downstream units are narrowband HO2S. Mixing them (or side to side) will cause incorrect readings and new fault codes. Always match bank/position and part number.