Exhaust Gas Recirculation (EGR) Cooling System Performance
The P2457 code means the vehicle's onboard diagnostic system has detected: Exhaust Gas Recirculation (EGR) Cooling System Performance. This is a serious severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- moderate
- Estimated cost
- $100 - $500 (parts and labor)
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Common Symptoms
- Check Engine Light on
- Possible reduced power or derate on diesels
- Coolant temperature may run higher than normal
Probable Causes (Ranked by Likelihood)
- EGR cooler restricted or failing to cool exhaust gas sufficiently High
- Low coolant level or restricted coolant flow to the EGR cooler High
- EGR temperature sensor fault Moderate
Frequently Asked Questions
Is P2457 serious?
Treat it seriously on a diesel. A restricted EGR cooler runs hot, and on several common applications a failing cooler progresses to internal coolant leaks — which turns a cooler job into a much bigger one. Check coolant level immediately and diagnose soon.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
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The computer compared exhaust temperature before and after the EGR cooler and found the cooler is not cooling as commanded.
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Check coolant level and condition first — a starved cooler cannot cool.
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On common-rail diesels (6.4L/6.7L Power Stroke notably), a plugging EGR cooler is a known failure that can progress to coolant loss — do not ignore this code.
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Verify the EGR temperature sensors before condemning the cooler.
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Meaning corroborated against this site's independently researched diesel-family pages for the same code (Power Stroke (single internal witness; a well-documented Ford diesel application — confirm against your make's service information)).
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
P2457 on Diesel, EV & Equipment
The same code ID appears across other engines and platforms. The diagnostic flow varies by manufacturer — these are the platform-specific breakdowns:
Commonly Affected Vehicles
- Diesel vehicles with EGR coolers (notably 6.4L/6.7L Power Stroke); confirm for your make
Related Codes
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