OBD-II code · Powertrain (generic, extended)
P2457 EGR Cooler Performance
The EGR cooler does not lower exhaust gas temperature as expected — typically internal coolant fouling, a partial blockage, or a cracked cooler that mixes coolant with exhaust gas.
Is it safe to drive with P2457?
Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.
Common causes
- Most likelyCooler internally clogged with soot
- PossibleCooler cracked, coolant entering exhaust
Symptoms
- Check engine light on
- Pinging or knocking under load
- Power loss and hesitation
- Possible rough idle
- Failed emissions inspection (NOx)
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 2–8 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Egr Cooler, Egr Temperature Sensor
Related codes
- P2454Diesel Particulate Filter Pressure Sensor Circuit Low
- P2455Diesel Particulate Filter Pressure Sensor Circuit High
- P2456DPF Differential Pressure Sensor Circuit Intermittent
- P2458DPF Regeneration Duration
- P2459Diesel Particulate Filter Regeneration Frequency
- P245AEGR Cooler Bypass Control Circuit Open Bank 1
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.