Powertrain, generic (extended)

P214B SCR NOx Catalyst Inlet Temperature Too High During Particulate Filter Regeneration

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P214B is limited to the regeneration phase. To burn soot out of the particulate filter, the engine control adds late injections or uses a separate exhaust fuel injector, and the oxidation catalyst converts that fuel into heat. The code sets when the gas leaving this hot zone arrives at the SCR inlet above the limit allowed during regeneration. Navistar's patent US20190232224 describes exactly this conflict: repeated regenerations push vanadium SCR material towards its sublimation point near 550 °C, so the layout and temperature control must keep the SCR below it. No manufacturer documents P214B publicly. Compared with P214A, suspicion falls on regeneration control: a dripping exhaust injector, excess post-injection or soot burning too fast. The control unit usually aborts the regeneration.

Likely causes

Exhaust fuel injector leaking or over-dosing during regeneration
Heavily loaded filter burning off too quickly
Excess post-injection quantity from a worn engine injector
Exhaust temperature sensor upstream of the SCR reading too high

Symptoms

  • Check engine light on, regeneration aborted
  • Filter warning or rising soot load because regeneration cannot finish
  • Reduced engine power

Repair estimate

DifficultyHardWorkshop job
Parts and labour€150–3,000
Time1–5 h

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

Parts involved

scr catalystaftertreatment fuel injectorexhaust gas temperature sensor

Related codes

P214AP214DP214CP20ECP2080P200C

References: patents.google.com, law.cornell.edu, law.cornell.edu.