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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What Are the Symptoms of P2457?
- Check Engine Light on
- Possible reduced power or derate on diesels
- Coolant temperature may run higher than normal
What Causes P2457? (Most Likely First)
- 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
Can I Still Drive with P2457?
Short distances only. P2457 is rated serious severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.
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
How Do You Diagnose P2457?
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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:
Which Vehicles Commonly Get P2457?
- Diesel vehicles with EGR coolers (notably 6.4L/6.7L Power Stroke); confirm for your make
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