P0131 on the 2023 Honda HR-V
The 2023 Honda HR-V was completely redesigned with a 2.0L naturally-aspirated four-cylinder engine (158 hp) replacing the previous 1.8L, built on the Civic platform. P0131 indicates the upstream O2 sensor (Bank 1, Sensor 1) is outputting persistently low voltage. This sensor provides critical air-fuel ratio feedback to the ECM and is located in the exhaust manifold before the catalytic converter.
Sensor Location
On the redesigned 2023 HR-V, the upstream O2 sensor is on the exhaust manifold of the 2.0L engine. The new Civic-based platform provides good engine bay access. The sensor is accessible from the top of the engine or from underneath, depending on your preference.
Symptoms
- Check engine light on
- Lower fuel economy (normally 30 MPG combined)
- Rough idle
- Possible hesitation
- Emissions test failure
- ECM may run rich to compensate
Causes
1. O2 Sensor Defect — High Likelihood
On a relatively new 2023 HR-V, the most likely cause is a sensor with a manufacturing defect. The Denso upstream sensor operates in the exhaust manifold where temperatures are high. A defective sensing element produces stuck-low voltage. This should be a warranty repair item.
2. Wiring or Connector Problem — Medium Likelihood
A loose connector, improperly routed harness, or heat damage to the sensor wiring can cause low voltage readings. On the new platform, factory assembly variations can occasionally affect wiring integrity. Inspect the connector and harness before assuming sensor failure.
3. Exhaust Manifold Leak — Medium Likelihood
An exhaust leak at the manifold gasket or at a cracked manifold stud introduces ambient air near the sensor. On a new vehicle, this would be an assembly issue — improperly torqued bolts or a damaged gasket. Listen for cold-start ticking as a diagnostic clue.
4. ECM Software Issue — Low Likelihood
As a first-year redesign, Honda may have software updates available that adjust O2 sensor monitoring thresholds. A TSB-related reflash could resolve P0131 without parts replacement.
Diagnosis
- Check TSBs — First step on a new-platform vehicle.
- Monitor sensor voltage — Stuck below 0.2V confirms P0131.
- Inspect wiring — Check connector seating and harness routing.
- Exhaust inspection — Listen and look for leaks at the manifold.
- Heater test — Verify sensor heater circuit function.
Warranty
The 2023 HR-V has Honda's 3-year/36,000-mile basic warranty, 5-year/60,000-mile powertrain warranty, and the federal emissions warranty. P0131 should be covered under warranty.
Costs (if out of warranty)
- O2 sensor (OEM): $175–$310
- Wiring repair: $90–$220
- Exhaust manifold gasket: $130–$280
- Software update: $0–$150
Dealer Is the Right Choice
On a 2023 model under warranty, take it to your Honda dealer. The HDS diagnostic system and access to TSBs make dealer service the right choice. The repair should be covered at no cost to you.