P0125 TOYOTA -

Question

THREE CODES FROM CHECK ENGINE LIGHT TODAY P0125 P1135 P0171
CHANGED THERMOSTAT AND COOLANT TEMPERATURE SENSOR WHAT NEXT?

Answer 1

Hi there,

Actually, even though it looks like a thermostat and coolant temp sensor issue, this is also caused by the bank 1 O2 sensor, sensor #1. After the engine is warmed up, it's not changing the voltage fast enough to make the computer happy. This will also cause the other codes, one is specific to the sensor, the other is a lean fuel mixture. This can be caused by a faulty O2 sensor.