P0131 on Toyota Corolla E140: O2 Sensor Circuit Low Voltage (Bank 1 Sensor 1)

Short answer: P0131 means “O2 Sensor Circuit Low Voltage (Bank 1 Sensor 1)”. The car’s computer has found a fault in the Emissions system and turns on the Check engine light (MIL). First check: read the code and live data with an OBD-II scanner.

Standard OBD-II code Same meaning on all cars (SAE J2012). Not checked against this car’s factory manual.

Code

P0131

System

Emissions

Dashboard light

Check engine light (MIL)

Applies to

Generic OBD-II meaning. Not every code is used by this car.

Confidence

medium (generic OBD-II definition, not checked against the factory manual for this car)

Source

obd-codes.com

Symptoms and when it is set

1. Check engine light on 2./ Service Engine Soon) illumination

Likely causes

1. Faulty o2 oxygen sensor
2. Short to voltage on O2 signal circuit
3. High resistance or open on O2 signal circuit

What to check, in order

1. Read the code and live data with an OBD-II scanner
2. Look for exhaust or vacuum leaks and check the wiring of the sensor or valve
3. Test the part before replacing it
4. Fix the cause, clear the code and test-drive

Related on this car

• All fault codes for this car
• Warning lights
• Where the parts are (parts map)
• Common problems

Same code on other cars

• P0131 · Toyota Passo (1st gen)
• P0131 · Toyota Corolla (11th gen, E170)
• P0131 · Honda City (5th gen, GM2)
• P0131 · Honda Civic (10th gen, FC)
• P0131 · Suzuki Wagon R (Pakistan, K10B)
• P0131 on all cars compared

← P0130 P0132 →

Clearing the code does not fix the fault. If it comes back, the problem is still there. For brakes, airbags and steering, see a trained mechanic.