Diesel Trouble Codes

P244B — Diesel Particulate Filter Differential Pressure Too High (Bank 1) (6.4 Power Stroke)

The PCM sees a pressure difference across the DPF that is higher than expected, indicating excessive restriction in the aftertreatment path. On the 6.4L Power…

Updated September 2, 2026

What it means

The measured pressure difference across the diesel particulate filter is higher than expected — the DPF is heavily soot- or ash-loaded (or a sensing hose is pinched, or the sensor reads high). A common 6.4L Power Stroke code when the DPF is plugging up and regens are not keeping pace. It is an aftertreatment / DPF code, NOT an EGR cooler bypass valve circuit code.1

Most likely causes

  1. DPF heavily soot- or ash-loaded from incomplete or aborted regenerations — Active regeneration uses in-cylinder late post-injection; if regens are interrupted or fueling is off, soot accumulates and delta-P rises. The platform uses DOC+DPF with active regen via late post-injection and has no SCR/DEF.1
  2. DPF differential-pressure sensor or sensing hoses fault (pinched, clogged, leaking, or sensor reading high) — A pinched/clogged or leaking sensing hose, or a biased sensor, can make the measured delta-P appear too high. The generic definition notes a sensing hose pinched or sensor reads high as a cause.1
  3. Excessive soot accumulation / restriction leading to limited power — Soot accumulation restricts exhaust flow; the platform lists P2463 as soot accumulation restriction and P246C as restriction – forced limited power.2
  4. Frequent or failed regeneration attempts increasing loading — Regenerations occurring more often than expected (P2459) can indicate the system is struggling to keep the DPF clean, contributing to high delta-P.3
  5. DPF efficiency degradation — Efficiency judged by pressure/temperature data can fall below threshold (P2002), consistent with a heavily loaded filter.4

How to diagnose

  1. Verify freeze-frame and monitor DPF differential pressure at idle and during a steady cruise; compare to expected values for temperature and load.
  2. Inspect DPF differential-pressure sensor and both sensing hoses for pinching, clogging, moisture, cracks, or loose connections; check for exhaust soot in hoses.
  3. Review recent regeneration history and frequency; check for P2459 (regen too frequent) and aborted regen conditions.
  4. Check exhaust back-pressure / delta-P trend with a scan tool while the engine is warm; look for high delta-P at low flow indicating physical restriction.
  5. Inspect for conditions that increase soot production or prevent complete burn-off, such as excessive fueling or oil dilution from late post-injection during regen.

Parts and tools you may need

Rough cost and difficulty

Diagnostic time is modest; DPF service or replacement is high cost. Do not perform safety-critical exhaust work without proper training and equipment.

When to see a pro

If delta-P remains high after confirming sensor/hoses are good, or if forced regeneration / DPF cleaning/replacement is being considered, have a qualified diesel aftertreatment technician evaluate the DPF condition and perform approved service. Do not attempt high-pressure fuel or exhaust system repairs without proper training.

Sources

  1. Curated DTC seed — 6.4 Power Stroke (curated) ↩︎ ↩︎ ↩︎

  2. Curated DTC seed — 6.4 Power Stroke (curated) ↩︎

  3. Curated DTC seed — 6.4 Power Stroke (curated) ↩︎

  4. Curated DTC seed — 6.4 Power Stroke (curated) ↩︎