Emissions

P0160 — O2 Sensor Circuit Malfunction (Bank 2 Sensor 2)

Severity: low Safe to drive

What P0160 means

P0160 means the engine control module detected no normal activity in the circuit of the downstream (post-catalytic converter) oxygen sensor on bank 2. This sensor lets the module judge catalytic converter efficiency by reading the exhaust after it. The signal is flat or out of range. Bank 2 is the side of the engine that does not contain cylinder 1.

Symptoms

  • Check Engine light on
  • Slightly higher fuel consumption
  • Occasionally a rough idle
  • Possible emissions test failure
  • P0420/P0430 catalyst codes may appear too

Possible causes

  1. Failed downstream O2 sensor on bank 2
  2. Broken, chafed or melted sensor wiring
  3. Corroded or loose connector
  4. Heater circuit fault (fuse, relay)
  5. Exhaust leak near the sensor
  6. Failing catalytic converter skewing readings
  7. Rarely, a faulty PCM

How to diagnose

  1. Scan for codes and freeze frame data, and note any other codes
  2. Confirm the sensor is the bank 2, post-catalyst one
  3. Inspect the sensor wiring and connector for damage, melting and corrosion
  4. Check the heater fuse and power supply to the sensor
  5. Watch live sensor voltage: it should change, not sit at one value
  6. Measure heater resistance and compare it with the spec
  7. Look for exhaust leaks or cracks upstream of the sensor
  8. Review fuel trims for an upstream mixture problem

Common fixes

  • Replace the bank 2 downstream O2 sensor
  • Repair the wiring or replace the connector
  • Fix the exhaust leak
  • Replace a bad heater fuse or relay
  • Replace or reflash the PCM only in rare, confirmed cases

Questions and answers

Can I drive with a P0160 code?

Usually yes, because engine operation is not noticeably affected. Still, get it diagnosed soon so a converter problem isn't missed and you can pass emissions.

Where is Bank 2 Sensor 2 located?

It sits in the exhaust after the catalytic converter, on the side of the engine without cylinder 1. The exact spot varies by model, so check the service manual.

Will replacing the sensor fix P0160?

Not always. Check the wiring, connector, heater fuse and exhaust leaks first, or the new sensor may set the same code.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.