Parts for your 2006 Nissan Serena-Oxygen sensor

2006 Nissan Serena Oxygen Sensor — What It Does and When to Replace It

Based on Nissan’s C25 Electronic Service Manual (EC section for MR20DE) and Nissan FAST parts catalogue, the 2006 Nissan Serena is fitted with exhaust gas sensors: an upstream air–fuel ratio sensor (Bank 1 Sensor 1) in the exhaust manifold and a downstream heated oxygen sensor (Bank 1 Sensor 2) after the catalytic converter. These sensors are integral to OBD-II emissions control used on the C25 platform from 2005. So yes, an oxygen sensor is relevant and fitted on the 2006 Serena.

On this Serena, the sensors constantly report how rich or lean the engine’s exhaust is. The engine control module uses that info to trim fuel, keeping the 2.0-litre MR20DE running smoothly, saving petrol, and protecting the catalytic converter. The upstream unit is a wideband air–fuel ratio sensor for precise control, the downstream heated oxygen sensor monitors catalyst efficiency and flags trouble if the cat isn’t doing its job.

As part of regular servicing, it’s smart to keep an eye on sensor health. A tired sensor can cause rough idle, higher fuel use, sluggish response and a glowing check-engine lamp. On scan tools, look for codes like P0130–P0141 or P2A00 (A/F sensor), and P0136–P0161 (downstream O2). If fuelling trims are constantly high, the upstream sensor may be drifting.

• Inspection: check wiring and plugs for heat damage or oil contamination, ensure no exhaust leaks ahead of the sensor.
• Intervals: many owners replace the upstream unit by around 120,000–160,000 km, and the downstream sensor as needed based on test results or codes.
• Replacement tips: use the correct Serena C25–spec sensor (avoid generic splice-in types), apply high-temp anti-seize on threads if the sensor isn’t pre-coated, and torque to spec from the ESM to avoid cracking the manifold.

After replacement, clear codes and run a short drive cycle so the ECU can relearn fuel trims. For grey-import Serenas, ensure the part numbers match the MR20DE calibration for the C25, as upstream sensors differ from conventional narrow-band O2 units. With healthy sensors, this Serena will start cleaner, cruise smoother, and sip less fuel—too easy.

Popular questions about the 2006 Nissan Serena oxygen sensor

Where are the sensors located on a 2006 Serena?
There’s one air–fuel ratio sensor threaded into the exhaust manifold close to the engine (Bank 1 Sensor 1) and one heated oxygen sensor after the catalytic converter under the floor (Bank 1 Sensor 2). Access to the upstream sensor is from the engine bay, the downstream one is typically reached from underneath.

What fault codes point to a bad oxygen sensor on a Serena?
Common codes include P2A00 or P0130/P0133 for the upstream air–fuel ratio sensor, and P0136/P0141 for the downstream heated O2 sensor. It’s worth checking for exhaust leaks and wiring faults before condemning the sensor.

Can the Serena be driven with a failed oxygen sensor?
It will usually run in a richer default strategy, which bumps up fuel use and can shorten catalytic converter life. Short trips to the workshop are generally fine, but it’s best to repair promptly to avoid extra costs and emissions test failures.