P20F0SCR NOx Catalyst Over Temperature (Bank 2)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- 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).
- What you may notice
- Malfunction indicator lamp on
- Reduced power or interrupted regeneration to protect the catalyst
- Likely causes
- 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
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €3,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.