P20F3: The NOx sensor before the catalyst on bank 2 is operating below the efficiency
The NOx sensor before the catalyst on bank 2 is operating below the efficiency threshold.
| Code | P20F3 |
|---|---|
| System | Engine and transmission |
| Group | P20xx, Emissions: catalysts and AdBlue |
| Type | Generic: it means the same on every make |
How to read and clear P20F3 with Final OBD
Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P20F3 with its description and whether it’s confirmed, pending or permanent.
If the engine stores it over standard OBD, with FREE you read this code with its explanation for nothing and clear it. With PRO you also read the faults of every control unit and clear them in all of them.
Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before an inspection. It’s all in how to read and clear fault codes and in inspections and OBD.
Similar codes
- P20EF The NOx sensor before the catalyst on bank 1 is operating below the efficiency
- P20F0 The SCR NOx catalytic converter (bank 2) is getting too hot
- P20F1 The NOx sensor before the catalyst on bank 2 is at an excessive temperature
- P20F2 The NOx sensor at the catalyst on bank 2 is operating below the efficiency
- P20F4 The AdBlue consumption gives a lower signal than normal
- P20F5 The AdBlue consumption gives a higher signal than normal
- P20F6 The AdBlue injector valve for unit 1 on bank 1 is stuck open
- P20F7 The AdBlue injector valve for unit 1 on bank 2 is stuck open
- P2002 Diesel particulate filter efficiency below threshold (bank 1)
- P2003 Diesel particulate filter efficiency below threshold (bank 2)
- P2004 Intake manifold runner control stuck open (bank 1)
- P2005 Intake manifold runner control stuck open (bank 2)
What does code P20F3 mean?
The NOx sensor before the catalyst on bank 2 is operating below the efficiency threshold.
How do you clear P20F3?
With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, P20F3 comes back.
Read it on your car
Final OBD reads and clears engine faults through standard OBD for free, each one explained in plain English. With PRO it also reads the faults of every control unit, each make’s own codes included, and clears them in all of them.
