• The fault code P0156 indicates that there is a malfunction in the circuitry of oxygen sensor 2 on bank 2, which is responsible for monitoring the exhaust emissions. This issue may lead to a decrease in engine performance and fuel economy.

Possible Symptoms:

  • Illuminated check engine light

  • Decreased fuel economy

  • Rough idling or stalling

  • Failed emissions testing

Possible Causes:

  • Failed Oxygen (O2) sensor (Bank 2 Sensor 2)

  • Damaged wiring or connections in the circuit associated with O2 Sensor in Bank 2 Sensor 2 (Check Fuse too)

  • Corrosion or loose connections in the sensor

  • Faulty Engine Coolant temperature sensor (or the associated circuit)

  • Failed Engine control module (ECM)

Related Parts:

  • Heated Oxygen Sensor: This is one of the parts that fails very commonly. It measures the amount of oxygen to ensure proper combustion. Problems in the Oxygen Sensor lead to poor fuel economy

Possible Solutions:

  • Replace the Oxygen (O2) sensor

  • Check and repair any damaged wiring or connections or Fuse

  • Clean or tighten any loose or corroded connections

  • Replace the engine control module (ECM) if necessary