Parts for your 2014 Nissan Serena-Oxygen sensor

2014 Nissan Serena oxygen sensor — what it does and how to look after it

Yes, the 2014 Nissan Serena (C26 series) is fitted with oxygen-sensing hardware. Nissan’s factory service literature for the C26 Serena (Engine Control/EC section) specifies an upstream Air-Fuel Ratio (A/F) sensor, often called Sensor 1, and a downstream Heated Oxygen Sensor (HO2S), Sensor 2, on the MR20-series petrol engine, including S-HYBRID variants. Nissan’s parts catalogues for C26 confirm these sensors, and the model’s OBD-II/OBD compliance in Japan and other markets from this era requires catalyst monitoring using front and rear oxygen sensors.

On the Serena, the front A/F sensor sits before the catalytic converter and constantly reports the exhaust’s oxygen content so the ECU can fine-tune fuel trims and keep the mixture right on the money for smooth running, good fuel economy, and low emissions. The rear HO2S sits after the cat and mainly checks the catalyst’s performance. If the cat’s doing its job, the rear sensor’s signal looks steady compared with the front’s rapid switching. Together, they help the Serena start easily, cruise efficiently, and pass emissions checks without a fuss.

There’s no strict time-based replacement interval in Nissan’s schedule, but these sensors are wear items. On many vehicles they drift with age somewhere after 150,000–200,000 kilometres, sooner if the engine has seen oil burning, coolant contamination, or leaded additives. Under the bonnet, a tired sensor can show up as higher fuel use, a bit of hesitation, rough idle, or a glowing MIL with codes like P0130–P0161 (sensor circuit/heater) or even P0420 (catalyst efficiency) once the rear sensor flags cat performance.

• Good reasons to replace: persistent fuel trim issues, a “lazy” sensor on live data, confirmed heater circuit faults, or catalyst efficiency codes after checking for exhaust leaks.
• Fitting tips: use the correct Serena-specific A/F or HO2S part numbers, don’t mix front and rear. Avoid contaminating the tip, handle the lead gently. If anti-seize is pre-applied on new sensors, don’t add more. Follow the EC/EM manual torque spec and route the harness exactly as clipped from factory.
• Diagnostics: rule out intake/exhaust leaks first, verify with a scan tool (short- and long-term trims, sensor response), and clear adaptations after replacement to let the ECU relearn.

Get the basics right and the Serena’s oxygen sensors will keep fuel economy tidy and the cat happy for many kilometres.

How many oxygen sensors does a 2014 Nissan Serena have?
Most 2014 Serena C26 models with the MR20-series petrol engine use two: an upstream Air-Fuel Ratio sensor (Bank 1 Sensor 1) and a downstream Heated Oxygen Sensor (Bank 1 Sensor 2). Some market variants and exhaust layouts can differ, but two-sensor setups are the norm for this generation.

If ordering parts, match by VIN to ensure the correct connector style and lead length. The front and rear sensors aren’t interchangeable.

What are the common signs of a failing oxygen sensor on a Serena?
Higher fuel consumption, a rough idle, hesitation on light throttle, and a Check Engine light are common clues. Scan-tool data may show slow sensor switching, stuck rich/lean readings, or fuel trims that are pegged trying to compensate.

Before blaming the sensor, check for exhaust leaks, intake leaks, or ageing spark plugs, as these can mimic sensor faults.

Can you drive a Serena with a faulty oxygen sensor?
You can usually drive short-term, but it’s not ideal. The ECU may default to richer mixtures, costing fuel and risking catalyst damage over time. If the heater circuit fails or trims go out of range, drivability can suffer and emissions will climb.

Sort it sooner rather than later to protect the cat and keep the fuel bill down.