P2457 — EGR Cooler A Efficiency Below Threshold

What Does P2457 Mean?

P2457 is a diagnostic trouble code indicating: EGR Cooler A Efficiency Below Threshold. This code relates to the powertrain system. It has been reported in NHTSA complaints across 2 different vehicle models.

Symptoms of P2457

⚠️ Check engine light illuminated

Common Causes

🔍 Stuck or failed EGR valve

P2457 Reports by Year

2018

1

2021

1

Real Owner Reports

From NHTSA complaint database — actual owner descriptions.

"THE CHECK ENGINE LIGHT COMES ON AND I FEELS A DECREASE IN THE ENGINE POWER. I COULD STILL DRIVE, BUT NOT ACCELERATE AS FAST. ERROR CODE READS P2457. TOOK TO DEALER WHO RECOMMEND TO REPLACE THE EGR COOLER, NOT COVERED BY WARRANTY. I ALSO HAVE BEEN EXPERIENCING FOUL ODOR IN THE PASSENGER COMPARTMENT W"
— Bmw X5 owner, 12/20/2018

"Plugged heater core. OBD code present P2457. Defroster was compromised. Confirmed by VW dealer. Advised by manufacturer to replace heater core and flush system per technical test and repair procedure."
— Volkswagen Passat owner, 09/02/2021

Source: NHTSA Complaints Database

Most Reported Vehicles for P2457

Based on NHTSA owner complaint data.

#	Vehicle	Reports
1	BMW X5
2	VOLKSWAGEN PASSAT

Frequently Asked Questions

Can I drive with this code?

It depends on the severity. If the vehicle runs normally, short trips are usually OK. If you notice performance issues, drivability problems, or warning lights beyond the check engine light, get it checked soon.

Will this code clear itself?

Some codes clear automatically after the underlying issue is fixed and several drive cycles pass. But the root cause must be addressed first.

How do I find the exact cause?

A code alone doesn't pinpoint the failed part. You need a diagnostic scan ($50-150 at most shops) that reads freeze frame data and live sensor readings to identify the specific component.

What To Do Next

Possible Fixes

🔧 Have the code scanned with a professional-grade scanner to read freeze frame data
🔧 If DIY repair isn't feasible, get a diagnostic from a trusted mechanic ($50-150)

1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

P2457: EGR Cooler A Efficiency Below Threshold