P20EE on Skoda
SCR NOx Catalyst Efficiency Below Threshold
P20EE on Skoda vehicles indicates scr nox catalyst efficiency below threshold. Au7o has documented this code across 1 Skoda model — most commonly on Scala. 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 Skoda range from $250 to $1,500, 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 Skoda by Model
Skoda Scala(1 issue)
- 1.6 TDI DPF clogging and oil dilution on short-journey use2019-2020
Scala diesels (1.6 TDI, EA288) used mainly for short urban trips suffer DPF (diesel particulate filter) clogging because the exhaust rarely reaches the ~600 C needed for regeneration, so soot accumulates. Incomplete/interrupted regenerations also cause engine-oil dilution (diesel injected for regen washes into the sump), which can raise oil level and degrade lubrication. This is a VW-Group EA288 TDI pattern, the Scala included; Euro 6 cars can additionally see NOx-sensor and AdBlue/SCR injector crystallisation faults.
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View P20EE across all makes →Frequently Asked Questions
What does P20EE mean on Skoda?▼
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 Skoda specifically, this code is documented across 1 model.
What causes P20EE on Skoda vehicles?▼
Common causes on Skoda: 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 Skoda?▼
Repair costs on Skoda range from $250 to $1,500, depending on the specific model and root cause.
Which Skoda models have P20EE documented?▼
Au7o has documented P20EE on 1 Skoda model: Scala.