OBD-II code · Powertrain (generic, extended)

P241F EGR Cooler B Efficiency Below Threshold

The temperature drop across EGR cooler B is below the calibrated threshold - cooler is fouled with soot, has internal scaling, or coolant flow is restricted. Recirculated gas reaches the intake hotter than designed, increasing NOx and combustion temperatures.

Is it safe to drive with P241F?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyCooler fouled with soot or scaled

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
Medium
DIY friendly
Best left to a mechanic
Typical labour
2–5 h
Emissions test
Likely to fail
Parts involved
Egr Cooler B

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.