Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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HOMESERVICE MANUALSFORD2021EDGE SE, 4WDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 12 (ENGINE CONTROLS - POWERTRAIN DTC CHARTS & DESCRIPTIONS (DIESEL))DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONSDTC P0420 - CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD (BANK 1)
2021 Ford Edge SE, 4WD
DTC P0420 - Catalyst System Efficiency Below Threshold (Bank 1)
2021 Ford Edge SE, 4WDSECTION DTC P0420 - Catalyst System Efficiency Below Threshold (Bank 1)
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P0420 - CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD (BANK 1)
| Description: | During a regeneration, the PCM expects the temperature across the OC to increase by a calibrated amount. This DTC sets when the increase in temperature is less than 40% of the expected maximum increase. | ||
| Possible Causes: |
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| Diagnostic Aids: | Verify there are no concerns present with the fuel system and EGT sensors. Monitor the EGT11 and EGT12 PIDs to determine the temperature change across the OC. | ||
| Application | Key On Engine Off | Key On Engine Running | Continuous Memory |
| All | GO to PINPOINT TEST RA . | ||
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.