Air/fuel ratio sensor, code P0031

Hi,

What brand sensor are you replacing it with? I'm asking simply because people are getting parts from online that just don't work properly.

IF that isn't the case, we need to first check the sensor itself. Here are the directions for doing it:

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2003 Toyota Truck Tundra 2WD V6-3.4L (5VZ-FE)
Air-Fuel Ratio (A/F) Sensor
Vehicle Power-train Management Sensors and Switches - Power-train Management Sensors and Switches - Computers and Control Systems Oxygen Sensor Testing and Inspection Component Tests and General Diagnostics Air-Fuel Ratio (A/F) Sensor
AIR-FUEL RATIO (A/F) SENSOR
INSPECTION

1. INSPECT HEATER RESISTANCE OF A/F SENSOR (Bank 1 Sensor 1)

a. Disconnect the sensor connector.

Pic 1
b. Using an ohmmeter, measure the resistance between terminals +B and HT.

Pic 2

If the resistance is not as specified, replace the sensor.

Torque: 20 N.M (200 kgf. Cm, 14 ft. Lbf)

c. Reconnect the sensor connector

2. INSPECT OPERATION OF A/F SENSOR

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If the sensor meets the manufacturer's specs, then I need to know if you have a live data scanner. I will need to know the short term fuel trims.

Let me know what you find or if you have other questions.

Joe