P20F3 OBD-II: SCR nox Pre- Catalyst Efficiency Below Threshold
P20F3 Severity
Will P20F3 go away on its own?
Once the vehicle's onboard system no longer detects the issue, most codes will disappear on their own. If your vehicle still has this code, however, it should be properly diagnosed to avoid a more serious problem.
For a proper diagnosis, RepairPal Certified shops have the equipment, tools, and expertise.
Moderate severity codes might not threaten the vehicle's safety or functionality immediately, but you should still get it diagnosed within a reasonable time frame to keep your car running well.
What causes OBD-II fault code P20F3?
Diesel Exhaust Fluid (DEF) is used to assist in converting leftover exhaust particles to harmless gases. In order to burn off those particles, the temperature of the exhaust system needs to increase. the injection of DEF Fluid into the exhaust stream brings Diesel Particulate Filter (DPF) up to temperature. The system is then able to convert harmful NOx to Nitrogen, Carbon Dioxide, and water. The Reductant Catalyst (SRC) was added to further reduce any NOx was still in the exhaust stream. The engine computer (PCM) monitors the Reductant Catalyst System's use of DEF and its ability to convert NOx to Nitrogen, Carbon Dioxide, and Water. If the Reductant Catalyst fails to perform its job efficiently, code P20F3 is set.
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What Does P20F3 Code Mean?
OBD-II Code P20F3 is defined as a SCR nox Pre- Catalyst Efficiency Below Threshold
Diesel Exhaust Fluid (DEF) is used to assist in converting leftover exhaust particles to harmless gases. In order to burn off those particles, the temperature of the exhaust system needs to increase. the injection of DEF Fluid into the exhaust stream brings Diesel Particulate Filter (DPF) up to temperature. The system is then able to convert harmful NOx to Nitrogen, Carbon Dioxide, and water. The Reductant Catalyst (SRC) was added to further reduce any NOx was still in the exhaust stream. The engine computer (PCM) monitors the Reductant Catalyst System's use of DEF and its ability to convert NOx to Nitrogen, Carbon Dioxide, and Water. If the Reductant Catalyst fails to perform its job efficiently, code P20F3 is set.
P20F3 Symptoms
- DPF regeneration may not occur
Common Problems That Trigger the P20F3 Code
- DEF contamination
- DEF injector failure
- Selective Catalytic Reduction (SCR) failure
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