P0161 OBD-II Trouble Code

Technical Description

Oxygen O2 Sensor Circuit Low Voltage (Bank 2, Sensor 2)

What does that mean?

It basically means the PCM detected either an excessive current draw, or an open or short in the circuit powering the oxygen sensor's heater circuit. This is in reference to the Heated Oxygen Sensor (2) located rear of catalytic converter (Bank 2).

Symptoms

There will likely be no obvious symptoms other than MIL illumination.

Causes

A code P0161 may mean that one or more of the following has happened:

• HO2S heater power circuit open
• HO2S heater ground circuit open
• HO2S signal tracking (due to oil or moisture in the connector)
• HO2S is damaged or has failed PCM has failed

Possible Solutions

• Replace HO2 Sensor
• Repair open or short in power circuit
• Repair open or short in ground circuit
• Repair damaged connector due to tracking

Need more help?

If you still need help regarding the P0161 trouble code, please post your question in our auto repair forums.

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