Parts for your 2015 Honda Accord-Oxygen sensor

2015 Honda Accord oxygen sensor – what it does and when to replace it

Yes, the 2015 Honda Accord uses oxygen-sensing hardware. Technical sources including the Honda Factory Service Manual (Engine Control/Fuel & Emissions) and standard OBD‑II design confirm it runs a wideband air‑fuel ratio (A/F) sensor upstream and heated oxygen sensor(s) (HO2S) downstream to manage fuelling and monitor the catalytic converter. OBD‑II emissions rules (EPA/ARB and equivalent ADR requirements) mandate downstream catalyst monitoring on modern petrol vehicles, so the sensor suite is standard equipment. On 2.4‑litre 4‑cylinder Accords there’s one upstream A/F sensor (Bank 1 Sensor 1) and one downstream HO2S (Bank 1 Sensor 2). On 3.5‑litre V6 models there are two banks, so two upstream A/F sensors and two downstream HO2S.

On this Accord, the upstream A/F sensor constantly measures exhaust oxygen content to let the engine computer fine‑tune the air‑fuel mixture for smooth running, power and economy. The downstream oxygen sensor sits after the catalytic converter and checks how effectively the cat is cleaning up emissions, it also helps the ECU detect cat degradation.

Owners typically won’t service these sensors in the same way they would filters or spark plugs, but they are wear items. Wideband A/F and HO2S units often last 160,000 km or more, but operating conditions matter. A tired or contaminated sensor can skew fuelling, hurt fuel economy, and trigger the Check Engine light.

• Common signs of trouble: poorer fuel economy, rough idle, flat spots on acceleration, failed emissions, and fault codes such as P0133, P0134, P0157, or catalyst‑efficiency codes.
• Good practice: fix any exhaust leaks, avoid silicone sealants that aren’t sensor‑safe, and keep the ignition system healthy—misfires can damage both sensors and the cat.
• Replacement tips: use quality OEM‑equivalent sensors (Denso/NTK are typical OE suppliers), match by engine and bank, and use an O2‑sensor socket. Most new sensors come pre‑coated threads, if not, apply a small amount of sensor‑safe anti‑seize and torque to spec. Route the loom exactly as factory and keep the connector clean and dry.
• Intervals: replace on failure or if long‑term fuel trims and performance indicate ageing. Many technicians recommend proactive upstream sensor replacement around 160,000–200,000 km, especially if economy has tapered off.

Whether it’s the 2.4‑litre or the V6, a healthy set of A/F and oxygen sensors helps the Accord run crisply, sip less fuel, and keep emissions in check. It’s a small part with a big say in how the car feels day to day.

Popular questions

How many oxygen sensors are on a 2015 Honda Accord?
The 2.4‑litre 4‑cylinder has two: one upstream wideband A/F sensor (Bank 1 Sensor 1) and one downstream HO2S (Bank 1 Sensor 2). The 3.5‑litre V6 has four: an upstream A/F and a downstream HO2S on each bank.

Can an ageing oxygen sensor really affect fuel economy?
Yes. A lazy upstream A/F sensor can cause the ECU to enrich or lean off the mixture too much, often trimming economy and drivability. Restoring a tired sensor frequently brings back smoother running and better kilometres per litre.

Should oxygen sensors be cleaned or just replaced?
They’re not serviceable items. Cleaning usually doesn’t restore proper response and can damage the sensing element. If diagnostics confirm a faulty sensor, replacement with a correct‑spec unit is the right move.