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Q: Service Engine Soon light is on in 2003 Toyota Tacoma

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The Service Engine Soon light is on. I checked and it gave me a code P0031. I need this problem fixed so I can get my truck smogged and registered.

Hello code P0031 is for an oxygen sensor Bank 1 Sensor 1 heater circuit malfunction. Electrical testing should be performed to verify that the oxygen sensor has a good heater, measuring the resistance of the heater. If the heater has good power to the oxygen sensor, see if the ground is being switch on by the PCM. If you need further assistance, a certified mechanic, such as one from YourMechanic, can come to your home or office to have your Service Engine Soon Light inspected and repaired.

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