Parts for your 2018 Honda Cr-v-Oxygen sensor

2018 Honda CR‑V oxygen sensor — what it does and when to replace it

Based on the 2017–2019 Honda CR‑V Service Manual (Fuel & Emissions), Honda dealer parts catalogues, and OBD‑II emissions requirements, the 2018 Honda CR‑V is fitted with oxygen-sensing hardware. Both engines offered that year — the 1.5‑litre turbo (L15B7) and the 2.4‑litre (K24W) — use a primary wideband air‑fuel ratio (A/F) sensor before the catalytic converter and a secondary heated oxygen sensor after the converter for catalyst monitoring. So yes, an oxygen sensor is absolutely relevant and used on this model.

On the 2018 CR‑V, the oxygen-sensor system helps the engine computer trim fuel precisely, keeping the mixture spot‑on for power, economy, and low emissions. The upstream A/F sensor reads rich/lean conditions with high accuracy so the ECU can fine‑tune fuelling in real time. The downstream O₂ sensor checks catalytic converter efficiency and flags issues before they become big repair bills.

They’re not a routine “replace every service” item, but they do wear out. Real‑world life varies with driving and fuel quality, many last well past 160,000 km. If the check engine light pops up with O₂ or A/F‑related codes, fuel use creeps up, the CR‑V smells a bit “eggy,” or it fails a WOF/rego emissions test, it’s time to investigate.

• Common symptoms: higher fuel consumption, hesitant throttle, rough idle, failed emissions, or a lit MIL.
• Typical fault codes include P0134/P0135 (A/F sensor circuit/heater), P0138 (rear O₂ high voltage), and P0420 (catalyst efficiency — often confirmed with sensor data).

Good service practice for the 2018 CR‑V oxygen-sensor setup:

• Inspect sensor wiring and connectors during major services, heat and road grime can cause intermittent faults.
• Check for exhaust leaks before or near the sensors, leaks can skew readings and trigger false codes.
• Use the correct OE‑spec sensors, mixing A/F and conventional O₂ types will cause drivability headaches.
• Avoid silicone sealants that off‑gas and contaminate sensors. If needed, use only sensor‑safe anti‑seize (many new sensors come pre‑coated).
• Follow the workshop manual for removal torque and harness routing, then clear codes and perform any required idle or fuel‑trim relearns.

If the vehicle does lots of short trips, burns a bit of oil, or uses lower‑quality petrol, consider earlier checks — those conditions shorten sensor life. A healthy oxygen-sensor system keeps the CR‑V running sweet, saves on fuel, and protects the catalytic converter.

Popular questions about 2018 Honda CR‑V oxygen sensors

How many oxygen sensors are on a 2018 CR‑V?
There are two per vehicle: a primary wideband air‑fuel ratio (A/F) sensor before the catalytic converter and a secondary heated oxygen sensor after it. Both are essential — one manages fuelling, the other monitors the cat.

Can I keep driving with a bad oxygen sensor?
It’ll usually still run, but expect higher fuel use, potential damage to the catalytic converter over time, and the risk of failing a WOF/rego inspection. Best to diagnose and sort it promptly.

Do oxygen sensors need routine replacement?
Not on a fixed interval. Replace when faulty or contaminated, or if diagnostics show slow response or stuck readings. Periodic inspection during major services helps catch issues early.