Get the app
Quick access from your home screen.
DTC codes / P23xx · Ignition system and misfire / P23B7
P23B7 means the engine computer has detected that the heater circuit inside the nitrogen oxide (NOx) sensor for bank 1 sensor 3 is not performing within its expected range, so the sensor cannot reach operating temperature. The computer monitors the heater's electrical current and response time, and it flags this code when the heater draws too much or too little current or fails to heat the sensor quickly enough.
Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.
Get the app
Quick access from your home screen.