P20EE on Peugeot
SCR NOx Catalyst Efficiency Below Threshold
P20EE on Peugeot vehicles indicates scr nox catalyst efficiency below threshold. Au7o has documented this code across 2 Peugeot models — most commonly on 3008, 308. This is a diesel emissions code meaning the Selective Catalytic Reduction (SCR) catalyst on Bank 1 is not cleaning up exhaust as well as it should. The SCR system sprays Diesel Exhaust Fluid (DEF) into the hot exhaust to convert harmful nitrogen oxides (NOx) into harmless nitrogen and water; NOx sensors before and after the catalyst tell the computer how well it is working. When the measured efficiency falls below the required threshold, this code sets. Because it is an emissions-protection code, it often triggers warning lights and can lead to reduced power or a speed limit (a 'derate') if left unfixed. Typical repair costs on Peugeot range from $300 to $1,200, depending on the specific model and root cause.
Common Causes of P20EE
- •Poor quality, contaminated, or wrong DEF fluid
- •Faulty or clogged DEF injector/dosing valve
- •Failed upstream or downstream NOx sensor
- •Degraded or failed SCR catalyst
- •Exhaust gas temperature sensor fault affecting dosing
- •Exhaust or DEF line leak
- •DEF line/heater problems (crystallization or freezing)
P20EE on Peugeot by Model
Peugeot 3008(1 issue)
- AdBlue System Malfunction2017-2026
The second-generation 3008 BlueHDi models are plagued by AdBlue system faults, including false level readings and crystallized injectors. The vehicle displays a countdown to engine disable even with a full AdBlue tank.
Peugeot 308(1 issue)
- AdBlue System Fault2014-2026
The AdBlue (SCR) system on BlueHDi engines triggers false fault warnings and countdown timers to engine disable. The NOx sensor and AdBlue injector are primary failure points, often caused by crystallized fluid.
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View P20EE across all makes →Frequently Asked Questions
What does P20EE mean on Peugeot?▼
P20EE stands for "SCR NOx Catalyst Efficiency Below Threshold." This is a diesel emissions code meaning the Selective Catalytic Reduction (SCR) catalyst on Bank 1 is not cleaning up exhaust as well as it should. The SCR system sprays Diesel Exhaust Fluid (DEF) into the hot exhaust to convert harmful nitrogen oxides (NOx) into harmless nitrogen and water; NOx sensors before and after the catalyst tell the computer how well it is working. When the measured efficiency falls below the required threshold, this code sets. Because it is an emissions-protection code, it often triggers warning lights and can lead to reduced power or a speed limit (a 'derate') if left unfixed. On Peugeot specifically, this code is documented across 2 models.
What causes P20EE on Peugeot vehicles?▼
Common causes on Peugeot: Poor quality, contaminated, or wrong DEF fluid, Faulty or clogged DEF injector/dosing valve, Failed upstream or downstream NOx sensor, Degraded or failed SCR catalyst, Exhaust gas temperature sensor fault affecting dosing. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P20EE on a Peugeot?▼
Repair costs on Peugeot range from $300 to $1,200, depending on the specific model and root cause.
Which Peugeot models have P20EE documented?▼
Au7o has documented P20EE on 2 Peugeot models: 3008, 308.