BMW
NOx sensor oxygen signal shorted.
P122F fault code: what it means
P122F: NOx sensor oxygen signal shorted.
Usual causes, most likely first
- failed NOx sensor
- wiring fault
P122F by make
What the repair usually costs
- AdBlue / SCR fault diagnosis (scan, NOx and doser tests)NZ$70–NZ$280 · A$80–A$300
- AdBlue tank assembly or SCR catalyst replacement (dealer part)NZ$3,150–NZ$8,600 · A$2,780–A$7,650
Not sure what P122F means on your car? Ask Credov.
Before you clear it
Write the code down or photograph the scanner first. A code that comes straight back after clearing points to a fault that is still there. A car whose codes were cleared just before you arrived may be hiding one: the scanner's readiness monitors show "not ready" for a while after codes are cleared.
Researched by Credov from manufacturer and workshop sources. A fault code points to where a fault may be; a workshop confirms it with a diagnosis. Browse all fault codes.