Parts for your 2020 Honda Odyssey-Oxygen sensor

2020 Honda Odyssey oxygen sensor — what it does and when to service it

Yes, the 2020 Honda Odyssey is fitted with oxygen sensors. Technical sources including Honda’s factory service information for the J35-series 3.5‑litre V6 (Fuel and Emissions section) and genuine parts catalogues show two upstream wideband air–fuel ratio sensors (one per bank) and two downstream heated oxygen sensors (one per bank) for catalyst monitoring. This layout also aligns with OBD‑II/ADR emissions requirements for closed‑loop fuel control and catalyst diagnostics on late‑model petrol vehicles.

On this Odyssey, the upstream air–fuel sensors constantly measure the exhaust’s oxygen content to let the engine computer fine‑tune the mixture in real time. That keeps fuel economy tidy, drivability smooth, and emissions low. The downstream oxygen sensors sit after the catalytic converters and primarily watch that the cats are doing their job, they don’t control fuelling directly but are crucial for emissions compliance and for spotting a tired catalyst early.

They’re generally “no‑schedule” items, but they do age. By 160,000–240,000 kilometres, upstream sensors can drift, leading to richer or leaner trims, higher fuel use, and a bit of a soggy throttle feel. Downstream sensors can slow down too, confusing catalyst diagnostics. During regular servicing, it’s smart to scan for stored fault codes and fuel trims, eyeball the sensor wiring under the bonnet and underbody for heat or road‑damage, and check for exhaust leaks that can mislead the sensors.

• Common clues the sensors need attention: check‑engine light (codes like P0134/P0154/P0420), noticeably higher litres per 100 km, rough idle, or a sulphur/rotten‑egg whiff.
• Best practice on replacements: use the correct spec sensors (wideband A/F upstream, HO2S downstream) from reputable brands, avoid cutting and splicing “universal” types on this engine.
• Fitment tips: work on a cool exhaust, use an O2 sensor socket, don’t twist the harness, and don’t add anti‑seize if the new sensor’s threads arrive pre‑coated.
• Afterwards: clear fault codes, perform an idle/PCM relearn if required, and verify trims and readiness monitors with a scan tool.

Access on the front bank is usually straightforward, the rear bank can be tighter for hands and spanners, so allow extra time. With healthy sensors, this Odyssey will run cleaner, sip less petrol, and keep its catalytic converters happy for the long haul.

Popular questions

How many oxygen sensors does a 2020 Honda Odyssey have?
It runs four in total: two wideband air–fuel ratio sensors ahead of the catalytic converters (one per bank) and two heated oxygen sensors after the converters to monitor catalyst efficiency.

When should the oxygen sensors be replaced?
There’s no fixed interval, but many are ready by 160,000–240,000 km. Replace sooner if there’s a fault code, poor fuel economy, or drivability issues. It’s fine to replace only the failed sensor, though high‑kilometre vehicles may benefit from doing the upstream pair together.

Can you drive with a faulty oxygen sensor?
Usually the vehicle will still run, but it may default to richer fuelling, burn more petrol, and risk catalyst damage over time. It’s best to sort it promptly to avoid bigger bills and to pass emissions checks.