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 helps reduce pollution is not working properly because a valve is stuck open.
The reductant injection valve is part of the system that injects a fluid to reduce emissions. If it's stuck open, too much fluid may be injected, causing issues.
The P20F6 code indicates that the reductant injection valve on Bank 1 Unit 1 is stuck in the open position. This valve is responsible for injecting Diesel Exhaust Fluid (DEF) into the exhaust stream to reduce NOx emissions. When the valve is stuck open, it can lead to excessive DEF consumption and potential damage to the system.
• Check engine light is on
• Increased DEF consumption
• Possible engine performance issues
• Faulty reductant injection valve
• Electrical issues in the valve circuit
• Contaminated DEF fluid
Reductant: A substance used to reduce emissions, often Diesel Exhaust Fluid (DEF).
SCR: Selective Catalytic Reduction, a system used to reduce NOx emissions in diesel engines.
• Check for any stored codes and freeze frame data.
• Inspect the reductant injection valve for physical damage.
• Test the electrical circuit of the valve for continuity and proper voltage.
• Replace the reductant injection valve if faulty.
• Repair any wiring or electrical issues in the valve circuit.
• Flush and replace contaminated DEF fluid.
• OBD-II scanner
• Multimeter
• Wrench set
$200 - $600
Moderate
• Ford F-250
• Chevrolet Silverado
• Dodge Ram 2500
• Regularly check DEF fluid quality and level.
• Perform routine maintenance on the exhaust system.
• Inspect electrical connections for corrosion or damage.
Emission Control System
• Do not ignore the check engine light.
• Consult a professional mechanic if unsure about repairs.
Check your vehicle's warranty for emission-related components, as they may be covered.
This code is relatively common in vehicles with SCR systems, especially in diesel engines.
Moderate – Address the issue to prevent further damage and maintain emissions compliance.
Operating a vehicle with a malfunctioning emission system may violate local emissions laws.
• Engine at operating temperature
• Vehicle in a stationary position
The reductant injection valve is typically located near the exhaust system, close to the SCR catalyst.
Q: Can I drive with a P20F6 code?
A: It's not recommended as it may lead to increased emissions and potential damage to the emission system.
Q: What happens if I ignore this code?
A: Ignoring the code can result in higher emissions, reduced fuel efficiency, and potential damage to the emission system.
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Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
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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.