Powertrain, generic (extended)

P243B Particulate Filter Restriction - Forced Limited Power (Bank 2)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P243B means the second particulate filter is so restricted that the engine controller cuts power to protect engine and filter. Ford documents the code in its 2024–2025 OBD summary for gasoline engines, as part of the petrol particulate filter monitor next to P246C for bank 1. Once the filter has been above 250 °C for 30 s and exhaust flow lies between 400 and 850 m³/h, a normalised back pressure above 1.0 for 5 s sets the fault. That makes it one of the few bank 2 filter codes with public thresholds, and it shows the code is not limited to diesels. Likely causes are a filter overloaded with soot or ash, a dented pipe, or a pressure sensor or hose reading too high. Until the restriction is cleared the engine stays in reduced power. A high soot load on this bank without the power limit is P243F.

Likely causes

Bank 2 filter overloaded with soot or ash
Damaged or blocked exhaust pipe on bank 2
Pressure sensor or hose on bank 2 reporting too high a pressure

Symptoms

  • Noticeably reduced engine power
  • MIL on
  • Poor acceleration at higher speed

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–2,500
Time0.5–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

dpf b2

Related codes

P246CP243FP24A3P226E

References: fordservicecontent.com, law.cornell.edu.