P0137 Lexus -

Question

I am getting the following codes: 137 (Low Voltage O2 Sensor), 138 (High Voltage O2 Sensor), 420 (Catalyst Efficiency), and 606 Engine Control Module at the same time.

Any suggestions as to what the problem is or what to replace first? We have already replaced the O2 sensor.

Answer 1

More than likely the problem is the catalytic converter, you probably have to replaced the converter to repair the problem.