Failure mode - Ford 6.7L Power Stroke Diesel (Scorpion)

EGR valve soot clogging / sticking

Reliability tier: verified - verify before ordering, see /disclosure/

Symptoms

rough idle, hesitation, or surging as a sticking valve mismeters exhaust gas
check-engine codes P0401 (insufficient EGR flow), P0402 (excessive flow), P0404/P0405 (valve position faults)
a valve caked in dry soot with sluggish actuation on inspection (vs a wet, steam-cleaned valve - see EGR cooler thermal-fatigue coolant leak)

Compare with the other causes of the same sign on this engine: misfire, rough idle, hesitation or surging (5 causes)

Root cause

Soot and unburned hydrocarbons progressively coat the EGR valve pintle, restricting flow until the system can no longer meet commanded EGR rates. Trucks that idle extensively or run short duty cycles clog fastest - the same short-trip pattern that drives DPF clogging / regeneration problems, and the two modes interact: a valve hanging open raises soot production and loads the DPF faster, while a clogged cooler/lazy valve pushes NOx up and increases DEF dosing demand (DEF / SCR / NOx sensor faults).

Diagnosis

command the valve through its range with a scan tool while watching position feedback for sticking or dead spots
distinguish from cooler failure (EGR cooler thermal-fatigue coolant leak): dry sooted passages = clogging; wet/steam-cleaned passages = coolant intrusion

Fixes

clean a lightly sooted valve to buy time ()

egr-valve - more than one option: 6.7L Power Stroke EGR Valve, Pickup (Wide Frame), 2015 to mid-2016 production, 6.7L Power Stroke EGR Valve, Pickup + Chassis Cab (unified), 2017-2019, 6.7L Power Stroke EGR Valve, Chassis Cab (Narrow Frame), 2015 to mid-2016 production - Service Kit, 6.7L Power Stroke EGR Valve, Pickup (Wide Frame), gen3

replace the valve when sticking persists after cleaning or actuation testing fails ()

egr-valve - more than one option: 6.7L Power Stroke EGR Valve, Pickup (Wide Frame), 2015 to mid-2016 production, 6.7L Power Stroke EGR Valve, Pickup + Chassis Cab (unified), 2017-2019, 6.7L Power Stroke EGR Valve, Chassis Cab (Narrow Frame), 2015 to mid-2016 production - Service Kit, 6.7L Power Stroke EGR Valve, Pickup (Wide Frame), gen3

Prevalence

common

Parts for this repair run about $270-$910: see them next to the other repairs on this engine in repair costs.