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Symptoms · 6.7 Power Stroke (2011-present)

6.7 Power Stroke (2011-present): loss of power, limp mode or derate

5 documented failures on this engine list this among their signs. They are ordered from the most widespread down. Each one shows the signs in its record's own words, how to tell it from the others, the usual fix and any recall or bulletin.

  1. DEF / SCR / NOx sensor faults Very common · 112 complaints
  2. CP4.2 high-pressure fuel pump contamination cascade Common · 171 complaints · 2 recall/bulletins
  3. Low-pressure fuel supply weakness (lift pump, filters, water-in-fuel) Common · 104 complaints
  4. DPF clogging / regeneration problems Common · 55 complaints · 2 recall/bulletins
  5. VGT turbocharger failure - generation dependent (ceramic-bearing GT32 vs journal-bearing GT37+) Occasional · 5 complaints

Not sure which engine you have, or want the recalls for your exact truck? Check your VIN: it names the engine and lists the campaigns for that model year. Whether a recall is still open on your VIN: nhtsa.gov/recalls.

1 DEF / SCR / NOx sensor faults
verified How widespread: Very common 112 NHTSA owner complaints match it, out of 1,754 checked

How it shows up

  • progressive derate warnings culminating in a 5mph limp if unaddressed
Its other signs
  • check-engine light with codes P20EE (SCR efficiency below threshold), P2200-series (NOx sensor circuit/performance), P204F (reductant/DEF system performance)
  • DEF warnings/low-dose faults that persist even with a freshly filled, good-quality tank

How to tell it apart

  • verify actual dosing BEFORE replacing any sensor: test DEF concentration with a refractometer, inspect the DEF injector tip for crystal buildup, confirm commanded dosing with a scan tool, check for exhaust leaks upstream of the sensors
  • NOx sensors are not cheap - do not condemn one without first ruling out the injector/DEF-quality/leak alternatives above

Usual fix

replace a confirmed-failed NOx sensor (upstream or downstream of the SCR catalyst) only after verifying dosing

Root cause, parts and sources →

2 CP4.2 high-pressure fuel pump contamination cascade
verified How widespread: Common 171 NHTSA owner complaints match it, out of 1,754 checked

How it shows up

  • loss of power that does not clear, often followed by a no-start
Its other signs
  • hard starting or a sudden stall, sometimes with no prior warning
  • fuel rail pressure DTCs P0087 (too low) / P0088 (too high), P0093 (large fuel leak detected), P008F (fuel/engine temp correlation)
  • metallic sheen or visible metal flakes in a cut-open fuel filter

How to tell it apart

  • cut open the fuel filter and inspect for metallic debris before doing anything else - its presence changes the whole repair scope
  • review rail-pressure command vs actual during cranking; pressure that will not build implicates the pump or pressure-control valve
  • rule out the low-pressure supply side (lift pump, filters - see Low-pressure fuel supply weakness (lift pump, filters, water-in-fuel)) before condemning the high-pressure pump

Usual fix

full fuel-system contamination kit: new/reman high-pressure pump + full injector set + rails + high-pressure lines + filters + seals in one job - replacing only the pump on a confirmed contamination event guarantees a repeat failure

Recalls and bulletins

26V-15824V-957

Root cause, parts and sources →

3 Low-pressure fuel supply weakness (lift pump, filters, water-in-fuel)
verified How widespread: Common 104 NHTSA owner complaints match it, out of 1,754 checked

How it shows up

  • hard starting, hesitation, or power loss under load consistent with low-pressure fuel starvation reaching the high-pressure pump
Its other signs
  • water-in-fuel (WIF) sensor warnings
  • fuel filter restriction/replacement-interval codes
  • visible fuel weeping/staining around the fuel filter housing - the factory PLASTIC housing is known to crack over time (S&S Diesel Motorsport product literature, via Dave's Auto Center)

How to tell it apart

  • always check the low-pressure supply side (lift pump, filters, WIF sensor) before condemning high-pressure components when diagnosing a starvation-type complaint
  • drain the water separator whenever the lamp requests it, and investigate repeated water warnings rather than just clearing them
  • inspect the fuel filter housing itself (not just the element) for hairline cracks or fuel weeping, especially on higher-mileage trucks - a housing crack is a durability issue the OEM filter change interval does not catch

Usual fix

replace the lift pump on confirmed low-pressure-side failure

Root cause, parts and sources →

4 DPF clogging / regeneration problems
verified How widespread: Common 55 NHTSA owner complaints match it, out of 1,754 checked

How it shows up

  • eventual limp mode if restriction is not addressed
Its other signs
  • frequent regenerations, more often than roughly every 100-200 miles of mixed driving
  • codes P2463 (DPF soot accumulation excessive) or P246C (DPF restriction)
  • a regen that never completes because the truck was shut down mid-cycle, compounding soot load on the next attempt

How to tell it apart

  • do not interrupt an active regen in progress (higher idle, running fans, changed exhaust smell are all normal during one)
  • a regen frequency well above 100-200 miles mixed driving points upstream: excessive idling, short trips, an EGR fault, or a biased differential-pressure sensor - not necessarily the DPF itself
  • P2463/P246C mean soot/restriction has outrun the regeneration strategy; forcing repeated manual regens on an already-restricted filter risks cracking the substrate

Usual fix

professional DPF cleaning for ash-loaded but structurally sound filters

Recalls and bulletins

Warranty Extension 20M06 (S1, S2)TSB 17-0053 / 18-2371

Root cause, parts and sources →

5 VGT turbocharger failure - generation dependent (ceramic-bearing GT32 vs journal-bearing GT37+)
verified How widespread: Occasional 5 NHTSA owner complaints match it, out of 1,754 checked

How it shows up

  • gen2/gen3 (2015-present): underboost code P0299, overboost P0234, actuator fault codes P0045-P0048, sluggish spool without the bearing-failure noise signature
Its other signs
  • gen1 (2011-2014): rising high-pitched whine/screech with engine speed, shaft play, oil consumption, blue-gray smoke, eventually wheel-to-housing contact
  • loss of exhaust-brake-like power under load
  • oil film or pooled oil in the charge piping (turbo seal transfer, vs normal light crankcase-vapor film)

How to tell it apart

  • listen at cold start and under load: a healthy turbo whistles evenly; a rising screech or a note that changes pitch under load points at bearings (gen1 signature)
  • with the intake tract opened, check compressor wheel shaft play - a small amount in/out is normal, side-to-side contactable play is not
  • pressure-test the charge-air system BEFORE condemning the turbo for a P0299 - boost leaks (see Intercooler condensation ingestion + cold-side charge-pipe fatigue) mimic turbo failure convincingly on this platform

Usual fix

gen1 (2011-2014): replace with an updated steel-bearing turbo assembly, not another ceramic-bearing original-design unit

Root cause, parts and sources →

Other symptoms on the 6.7 Power Stroke (2011-present)

Hard start, long crank or no-startWhite smoke from the exhaustLosing coolantOil leak, oil consumption or rising oil levelTicking, knocking, rattle or whineMisfire, rough idle, hesitation or surgingDEF, DPF and regeneration warnings

Everything on the 6.7 Power Stroke (2011-present)Its recalls and bulletins

Order: how widespread each failure is in its record (near-universal, very common, common, occasional, rare), then the number of NHTSA owner complaints that match its keywords. Complaint counts are keyword matches, not a manual review of each complaint. A symptom listed here means the failure is documented with that sign; it is not a diagnosis of your truck. Tiers: verified, aggregated, contested, data-gap. How we tier and source facts.