P20F0 code meaning
SCR NOx Catalyst Over Temperature (Bank 2)
Powertrain system Generic code P20xx codes Check engine light
What P20F0 means
P20F0 is the bank 2 version of P20EC: the SCR catalyst in the second exhaust line has been exposed to temperatures above its permitted limit. It presupposes a V engine with one aftertreatment path per bank, which is rare; most diesels merge both banks into one SCR line and use only the bank 1 codes. No manufacturer documents P20F0 publicly. The physical background is the same as on bank 1: vanadium-based coatings degrade by sublimation above about 550 °C (Navistar patent US20190232224), and the US heavy-duty rule 40 CFR 1036.115 requires the engine design to keep the catalyst below its sublimation threshold. When only one bank overheats, the cause tends to sit on that bank, for instance a leaking injector, a misfiring cylinder or a wrong temperature sensor. Repeated events can permanently lower the bank 2 conversion (P20F2).
P20F0 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor1 to 5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P20F0
- Malfunction indicator lamp on
- Reduced power or interrupted regeneration to protect the catalyst
Common causes of P20F0
- Most likelyLeaking injector or misfire on bank 2 sending fuel into the exhaust
- PossibleExcess heat during particulate filter regeneration on bank 2
- PossibleBank 2 SCR temperature sensor reading too high
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
SCR catalystExhaust gas temperature sensor
What each part of P20F0 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 0 | Area: fuel and air metering and auxiliary emission controls. |
| F0 | The exact fault in that area. |
What to do next
- Note P20F0 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P20F0
What does P20F0 mean?
P20F0 means "SCR NOx Catalyst Over Temperature (Bank 2)". P20F0 is the bank 2 version of P20EC: the SCR catalyst in the second exhaust line has been exposed to temperatures above its permitted limit. It is a generic code, so it means the same on every make.
Is it safe to drive with P20F0?
Drive gently and only to a workshop. With P20F0 the car can go into limp mode (reduced power) to protect itself.
Will P20F0 fail an emissions test?
Yes, it can. P20F0 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P20F0 to fix?
Difficulty: hard. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will P20F0 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.