P0131 on the 2024 Toyota Camry
The 2024 Toyota Camry features a 2.5L four-cylinder (203 hp) or a 2.5L hybrid powertrain (225 hp combined). P0131 indicates the upstream O2 sensor (Bank 1, Sensor 1) is producing persistently low voltage. On the Camry's inline-four, there's only one bank, and the upstream sensor sits in the exhaust manifold before the catalytic converter, providing critical air-fuel ratio feedback to the ECM.
Sensor Location
On the 2024 Camry, the upstream O2 sensor is threaded into the exhaust manifold at the front of the engine. Toyota's TNGA platform provides good access from above, making this one of the easier O2 sensor locations to reach. The sensor uses a Denso four-wire connector with signal and heater wires.
Symptoms
- Check engine light on
- Reduced fuel economy (normally 32 MPG combined; may drop 2–4 MPG)
- Rough or unstable idle
- Possible hesitation
- Emissions test failure
- ECM may run rich to compensate
Common Causes
1. Defective O2 Sensor — High Likelihood
On a new 2024 Camry, a manufacturing defect is the most likely cause. Toyota uses Denso wideband sensors that are generally very reliable, but no manufacturing process is perfect. A defective sensing element or heater produces stuck-low voltage from early use. This is a warranty repair.
2. Wiring or Connector Problem — Medium Likelihood
A loose connector, pinched wire, or heat-damaged insulation near the exhaust manifold can reduce signal voltage. On the Camry, the sensor harness is well-routed, but factory assembly variations can occasionally affect connections.
3. Exhaust Leak Near the Sensor — Medium Likelihood
A leak at the exhaust manifold gasket or at the sensor bung allows ambient air into the exhaust, causing the sensor to genuinely read lean. Even a small leak affects sensor accuracy. Toyota's integrated exhaust manifold design on the 2.5L reduces but doesn't eliminate this possibility.
4. ECM Software Issue — Low Likelihood
Toyota may have a software update that adjusts sensor monitoring parameters for the 2024 model year. A TSB-related reflash can sometimes resolve P0131 without hardware changes.
Diagnostic Steps
- Check for TSBs — Toyota dealer checks for applicable bulletins.
- Monitor sensor voltage — Stuck below 0.2V confirms P0131.
- Inspect wiring — Check the connector and harness near the exhaust manifold.
- Exhaust leak check — Listen for cold-start ticking and look for soot trails.
- Heater circuit test — Verify proper heater operation.
Warranty
The 2024 Camry has Toyota's 3-year/36,000-mile basic warranty, 5-year/60,000-mile powertrain warranty, and the federal emissions warranty (8 years/80,000 miles). The upstream O2 sensor should be covered under warranty.
Costs (if out of warranty)
- O2 sensor (OEM Denso): $180–$330
- Wiring repair: $90–$220
- Exhaust manifold gasket: $130–$280
- Software update: $0–$150
Dealer Service
On a 2024 Camry, visit your Toyota dealer. The Techstream diagnostic system provides detailed data, and the repair should be covered under warranty. Toyota's reliability reputation makes early sensor failures uncommon, so the dealer will investigate thoroughly.