Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
The car's system that reduces pollution is getting too hot, which could be bad for the car's health.
The Selective Catalytic Reduction (SCR) system is designed to reduce nitrogen oxide emissions. This code indicates that the temperature before the catalyst in Bank 1 is too high.
The P20ED code is triggered when the SCR system's pre-catalyst temperature sensor detects a temperature that exceeds the manufacturer's specified threshold. This could indicate a malfunction in the SCR system or related components, leading to potential damage if not addressed.
• Check Engine Light is on
• Poor engine performance
• Increased emissions
• Faulty NOx sensor
• Malfunctioning temperature sensor
• Exhaust leaks near the sensor
SCR: Selective Catalytic Reduction, a system used to reduce nitrogen oxide emissions.
NOx: Nitrogen Oxides, pollutants produced during combustion.
• Use an OBD-II scanner to confirm the code.
• Inspect the NOx and temperature sensors for damage.
• Check for exhaust leaks near the SCR system.
• Replace the faulty NOx sensor.
• Repair or replace the temperature sensor.
• Fix any exhaust leaks.
• OBD-II scanner
• Multimeter
• Wrench set
$200 - $600
Moderate
• Ford F-250
• Chevrolet Silverado
• Ram 1500
• Regular maintenance of the exhaust system
• Timely replacement of sensors
• Avoiding excessive idling
Sensor Issue
• Do not ignore the Check Engine Light.
• Consult a professional mechanic for a thorough inspection.
Check with the vehicle manufacturer for specific warranty coverage on emissions-related components.
This code has become more common with the increased use of SCR systems in diesel engines to meet emissions standards.
Moderate – Addressing this issue promptly can prevent further damage to the SCR system.
Operating a vehicle with this issue may lead to increased emissions, which could violate local emissions laws.
• Engine at operating temperature
• Vehicle driven at various speeds
The SCR system and its sensors are located in the exhaust system, typically under the vehicle.
Q: Can I drive with a P20ED code?
A: It's not recommended to drive for extended periods with this code, as it may lead to further damage.
Q: How can I prevent this code from appearing?
A: Regular maintenance and timely replacement of sensors can help prevent this issue.
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Good for emissions-related codes because it exposes readiness monitors and live powertrain data.
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Helpful for finding EVAP and vacuum leaks that are hard to see with visual inspection alone.
Helpful for tracking down EVAP and vacuum leaks that can trigger emissions faults.
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Specialty · O2 sensor socket
Helpful when the code points toward exhaust or oxygen-sensor work and space is tight.
Useful when the diagnosis points toward oxygen-sensor removal or replacement.
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Fitment Required · Vehicle-fitment part
Relevant when catalyst-efficiency or emissions faults persist after proper diagnosis.
Catalyst-efficiency faults sometimes point toward converter problems after proper testing.
Catalytic converters are highly vehicle-specific and should not be purchased by code alone.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.