P2221 OBD II Trouble Code NOx Sensor Heater Sense Circuit Bank 2

How to quickly diagnose, repair, and causes of a P2221 diagnostic code that means that a malfunction has been detected within the NOx sensor heater sense circuit on bank 2.

Symptoms of P2221 OBD II Trouble Code

  • Intermittent stalling
  • The engine fails to start when warm
  • Decreased performance of the engine
  • When accelerating, there may be a hissing and/or hesitation
  • The engine might run lean or rich on bank #2 exclusively

Common Causes of P2221 OBD II Trouble Code

  • Catalytic converter is malfunctioning
  • Incorrect fuel mixture
  • The coolant temperature sensor is faulty
  • The manifold air pressure sensor is broken
  • There are problems with the mass air inflow sensor
  • The fuel injection part is defective
  • The fuel pressure regulator is broken
  • There were ignition misfires
  • There are leaks from the exhaust manifold, flex hose, down pipe, or some other exhaust component
  • Broken oxygen sensors

Severity of P2221 OBD II Trouble Code

If the trouble codes are ignored and that there weren't any action made to repair it could lead to catalytic converter failure. If the symptoms and causes of these trouble codes are left unattended, it could lead to further complications for your car such as consistent stalling and reduced fuel economy. If you notice any of the potential symptoms in the list below, it is highly recommended to have it checked by a professional.