Powertrain, generic (extended)

P214C SCR NOx Catalyst Outlet Temperature Too High

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P214C looks at the downstream end of the SCR catalyst: the temperature measured behind it rose above the permitted maximum outside regeneration. California's OBD rule lists SCR intake and outlet temperature as separate data values a diesel must report, so both points are watched on their own. An outlet reading that climbs above the inlet value hints at heat produced inside or just ahead of the brick, for instance hydrocarbons burning on the SCR or soot glowing in a combined filter-SCR unit, but a faulty outlet sensor is just as likely. The material limit is the same as on the inlet side, which 40 CFR 1036.115 and Navistar's patent US20190232224 describe for vanadium catalysts. No manufacturer documents P214C publicly. P214A is the inlet counterpart, P214D the outlet fault during regeneration.

Likely causes

SCR outlet temperature sensor faulty or reading too high
Hydrocarbons passing the oxidation catalyst and burning on the SCR
Fuel or oil entering the exhaust from the engine or turbocharger

Symptoms

  • Check engine light on
  • Reduced engine power
  • Implausible outlet temperature compared with the inlet value in live data

Repair estimate

DifficultyMediumWorkshop 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

scr catalystexhaust gas temperature sensor

Related codes

P214DP214AP214BP20ECP242B

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