Error Code P0160 is defined as O2 Sensor Circuit No Activity Detected Bank 2 Sensor 2. It is normally set when there’s no activity detected on the Bank 2 Sensor 2 of the Oxygen (O2) Sensor circuit. This happens when the voltage signal sent from the sensor to the PCM (powertrain control module, also called as engine control module or ECM) is constant, which means there’s a fault in the circuit.

It’s a generic trouble code, meaning it applies to all vehicles equipped with OBD-II equipment, especially vehicles made since 1996 up to present. Specifications on the definition, troubleshooting and repairs of course, vary from one make and/or model to another.


Error Code P0160 means the code for post-catalyst O2 sensor is not operating properly, or not operating at all. The job of the catalyst converter (or simply known as the ‘catalyst’) is to control emissions. The specified oxygen sensor at Bank 2 Position 2 is after the converter on Bank 2, and checks the efficiency of the catalytic converter on that bank.

To measure the efficiency of the catalytic converter, the PCM then compares the post-cat O2 sensor to the pre-cat O2 sensors. The oxygen sensor is made up of four wires, and the PCM supplies half a volt (0.5V) for reference voltage to the sensor through one wire, and sensor ground to the other wire. For the heater element, 12V is supplied as well as ground. The job of the heater is to help ensure the sensor warms up faster, allowing the engine to reach a closed loop faster.

The PCM changes the reference it sends to the sensor based on the amount of oxygen on the exhaust. Changes in oxygen content cause changes in resistance in the sensor, affecting the 0.5V reference voltage. A rich exhaust results to high voltage, causing the supplied volts (0.5V) to increase. For the pre-catalyst (front) O2 sensors, the switch between low and high voltage should be quick, which is around once or twice per second. The post-cat however, changes a little slower, which is normal.

If there are too few switches in a specified time however, if the sensor “sticks” then that’s a problem of Error Code P0160.

Common Symptoms

The most obvious symptom for this code is the illumination of the Check Engine light.

The tricky thing about this code is that it doesn’t usually cause any obvious drivability problems other than reduced fuel economy.

Possible Causes

As said earlier, this code is set when there is no activity on the O2 sensor circuit, Bank 2 Sensor 2. This thing usually happens when:

  • There are holes in the exhaust, especially near the post cat O2 sensor
  • Wiring problem, broken connectors, chaffed wires, melted harness, etc.
  • Bad Bank 2, Position 2, Oxygen Sensor
  • Bad PCM (rare)

How to Check

As with most error codes, diagnosing P0160 requires a visual test of the O2 sensor harness. Check for any signs of damage. This side of the vehicle is extremely susceptible to damage usually caused by road hazards.

Then, check the terminal connectors for signs of corrosion and/or water intrusion. These problems can cause incorrect voltage readings which usually lead to the error code.

Then, check the resistance of the O2 sensor and make sure it meets the specifications.

If the resistance of the O2 sensor is in good condition, proceed to measure the reference voltage supplied by the PCM.

If everything seems okay, that means the O2 sensor is at fault. Conduct a quick test by monitoring the voltage of the sensor using a scan tool. You can either introduce a vacuum leak or extra fuel source to the vehicle.

The test should show a change to the voltage reading to extreme end or the other for the sensor. If there are no changes, that means the sensor is not reading correctly.

How to Fix

The easiest way to repair this error code is to replace the faulty O2 sensor.

If the O2 sensor is not at fault, then there must be problems with the wiring, which should be repaired or replaced as needed.

Error Code P0160 is actually not something to worry about. It will not cause drivability problems. However, it will cause the vehicle to fail emission tests if the test equipment is connected to the PCM to check for codes.