Question

My 2003 Toyota Sienna 3.3L consumes too much fuel. What do I do? Which sensor is responsible? I got the engine code P0031

Answer 1

Hi there

This code is for a bad heater control circuit in the front O2 sensor on bank 1. This wouldn't typically cause a huge loss in economy. You might want to check into a tune up. If it's been over 60k since the spark plugs have been changed it might be the best place to start. Low tire pressure and a dirty air filter can cause poor mileage as well. Here is some more info on the code.

P0031 TOYOTA - Oxygen Sensor Heater Control Circuit Low Bank 1 Sensor 1
Read more: https://www.autocodes.com/p0031_toyota.html