Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's system that cleans up harmful gases isn't working well enough. It's like when a filter gets clogged and can't clean things properly.
The Selective Catalytic Reduction (SCR) system is not reducing nitrogen oxides (NOx) emissions as expected.
The P2C7A code indicates that the efficiency of the SCR system's NOx catalyst on Bank 1, Catalyst 2, is below the expected threshold. This means the catalyst is not effectively reducing NOx emissions, which could be due to a malfunction in the catalyst itself or related components.
• Check Engine Light is on
• Reduced fuel efficiency
• Increased emissions
• Faulty SCR catalyst
• Defective NOx sensor
• Exhaust leaks
SCR: Selective Catalytic Reduction
NOx: Nitrogen Oxides
• Use an OBD-II scanner to confirm the code.
• Inspect the SCR catalyst and NOx sensors for damage.
• Check for exhaust leaks.
• Replace the SCR catalyst if faulty.
• Replace defective NOx sensors.
• Repair any exhaust leaks.
• OBD-II scanner
• Wrench set
• Multimeter
$500 - $2000
Moderate
• Ford F-250
• Chevrolet Silverado
• RAM 2500
• Regular maintenance of the emission system
• Use high-quality fuel
• Timely replacement of sensors
Emission Control System
• Avoid driving long distances until repaired.
• Monitor fuel efficiency and emissions.
• Consult a professional mechanic for diagnosis.
Emission system components may be covered under the vehicle's emissions warranty.
This code has become more common with the increased use of SCR systems in diesel vehicles to meet emission standards.
Moderate – Addressing this issue is important to maintain vehicle efficiency and comply with emission standards.
Operating a vehicle with this issue may violate emissions regulations and contribute to air pollution.
• Engine at operating temperature
• Vehicle driven at various speeds
The SCR catalyst is located in the exhaust system, typically near the vehicle's undercarriage.
Q: Can I drive with a P2C7A code?
A: You can drive short distances, but it's best to fix it soon to avoid increased emissions and potential engine damage.
Q: What happens if I ignore this code?
A: Ignoring it can lead to higher emissions, reduced fuel efficiency, and possible damage to the emission system.
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A wired color-screen reader with readiness hotkeys, live data, code definitions, and data logging.
Good for emissions-related codes because it exposes readiness monitors and live powertrain data.
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Specialty · Smoke machine
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.