Parts for your 2019 Nissan Serena-Oxygen sensor

2019 Nissan Serena Oxygen Sensor (C27): What It Does and When to Replace It

Yes — the 2019 Nissan Serena (C27) uses oxygen-sensing hardware. Technical documentation for the C27 platform shows an upstream air–fuel ratio (A/F) sensor before the catalytic converter and a downstream heated oxygen sensor (HO2S) after the cat on the MR20DD 2.0-litre S-HYBRID, and likewise on the e-POWER variant with the HR12DE engine. See: Nissan Serena C27 Electronic Service Manual, Engine Control (EC) section, Nissan C27 parts catalog (A/F Sensor 1 and Rear O2 Sensor listings), and OBD-II/J-OBD/EOBD regulations requiring pre- and post-catalyst monitoring on petrol engines. That makes the oxygen sensor 100% relevant to servicing a 2019 Serena.

On this Serena, the upstream A/F sensor is the engine’s “eyes” for fuelling — it tells the ECU how rich or lean the mixture is so the engine can run smoothly, cleanly and efficiently. The downstream O2 sensor’s main job is to keep tabs on catalytic converter performance. Together they help with cold starts, cruising economy, throttle response and emissions. If either sensor gets sluggish or fails, the ECU can swing the mixture off target, fuel economy drops, emissions go up, and the cat can cop a hiding over time.

There’s no hard-and-fast replacement interval — many last beyond 160,000 km — but they are wear items. Good practice for a 2019 Serena service plan is:

• Scan for fault codes and check fuel trims at every major service (or if the check engine light’s on). Codes like P013x/P015x or sustained trims beyond ±10% are a clue.
• Visually inspect the sensor wiring and connector boots for heat damage or oil ingress.
• Chase any exhaust leaks before the cat — they can skew readings and trigger false faults.
• Use OEM or high-quality direct-fit sensors, avoid universal splice-in types on late-model Nissans.

Replacement tips a tech would follow: let the exhaust cool, use an O2 sensor socket, and don’t contaminate the tip. Most modern sensors arrive with the correct thread coating — no extra anti-seize unless the manufacturer specifies it. After fitting, clear codes and run a drive cycle so the ECU can relearn. If the Serena is an e-POWER model, the engine still relies on these sensors for its generator operation, so the same checks apply.

Common signs it’s time to act include higher fuel use, rough idle, sulphur/rotten-egg smell, failed WOF/rego emissions sniff, or a persistent MIL. Staying on top of this small part keeps the big-ticket items — like the catalytic converter — happy, and helps the Serena stay frugal on long Kiwi and Aussie runs.

Popular questions about 2019 Nissan Serena oxygen sensors

How often should the oxygen sensors be replaced on a 2019 Serena?
There’s no fixed kilometre interval. Many last 160,000–200,000 km, but city driving, short trips and oil or coolant contamination can shorten life. Best bet: test by data (fuel trims, sensor response) at each major service and replace on condition or if codes/logs point to a lazy sensor.

Where are the sensors located on the C27 Serena?
There’s one upstream A/F sensor screwed into the exhaust manifold or front pipe before the catalytic converter, and one downstream heated O2 sensor after the cat. Both are on Bank 1 as the Serena’s engines are inline layouts. Access varies with engine variant and whether it’s 2WD or 4WD, but both are reachable from underneath with the right socket.

Can it be driven with a faulty O2 sensor?
Usually yes for a short period, but fuel economy and performance can suffer, and long-term running rich risks damaging the catalytic converter. If the MIL is flashing or there’s a strong fuel/sulphur smell, park it and get it checked to avoid bigger bills.