Diesel Trouble Codes

P2002 — Diesel Particulate Filter Efficiency Below Threshold (Bank 1) (6.7 Cummins (EGR + DPF, pre-SCR))

Diagnostic reference for 6.7 Cummins 2007.5–2012 EGR+DPF pre-SCR. P2002 indicates the ECM judges DPF filtering efficiency below threshold using…

Updated September 2, 2026

What it means

The ECM has determined DPF filtering efficiency is below threshold based on pressure/temperature data. Generic definition: DPF filtering efficiency, judged by pressure/temperature data, is below threshold. Platform has EGR + DOC/NAC + DPF, no SCR/DEF.1

Most likely causes

  1. DPF physically restricted / ash loaded, causing abnormal differential pressure and reduced efficiency — Excess soot/ash raises delta-P and temperature profile; ECM interprets as efficiency below threshold. Generic definition ties efficiency to pressure/temperature data.1
  2. DPF differential-pressure sensor or its tubing giving skewed readings — Erroneous delta-P input can cause false efficiency calculation. DPF pressure sensor circuit faults are documented for this platform.2
  3. Insufficient or failed regenerations leading to accumulated soot — Frequent or missed regens are a known DPF health driver on this platform. Regeneration frequency monitoring exists.3
  4. Excessive oil consumption / injector over-fueling increasing soot load — More soot production raises DPF load and efficiency monitor. Injector circuit faults are tracked on this platform.4
  5. Aftertreatment temperature sensing error affecting efficiency calculation — Efficiency monitor uses temperature data; sensor drift can bias the calculation. Generic definition references pressure/temperature data.1
  6. ECM / calibration / aftermarket tuning misreporting efficiency — Atypical catalyst/efficiency codes can appear with non-standard calibrations. P0420 is noted as atypical/rare and often misapplied on this platform.5

How to diagnose

  1. Verify freeze-frame and confirm P2002 is active with DPF-related data present.
  2. Inspect DPF differential-pressure sensor and tubes for soot plugging, cracks, or leaks; compare sensor voltage to spec at idle and elevated RPM.
  3. Review regen history and frequency; excessive regen frequency points to loading issues.
  4. Check exhaust backpressure and temperature sensor readings for plausibility vs. expected values.
  5. Inspect for oil consumption, blow-by, injector balance, and fuel system health; injector faults are monitored on this platform.
  6. Confirm calibration/ECM software is OEM for 2007.5–2012 EGR+DPF pre-SCR; non-OEM tuning can cause spurious efficiency codes.

Parts and tools you may need

Rough cost and difficulty

Cost varies by root cause. Sensor/tubing service is low cost; DPF cleaning/replacement is high cost. Diagnosis should confirm actual restriction before replacing DPF.

When to see a pro

If diagnosis points to internal DPF failure, removal and professional cleaning/testing is required. Do not attempt high-pressure fuel system service; CP3 high-pressure pump failures have caused sudden engine stoppage under load. See a professional for aftertreatment service and fuel system work.

Sources

  1. Curated DTC seed — 6.7 Cummins (EGR + DPF, pre-SCR) (curated) ↩︎ ↩︎ ↩︎

  2. Curated DTC seed — 6.7 Cummins (EGR + DPF, pre-SCR) (curated) ↩︎

  3. Curated DTC seed — 6.7 Cummins (EGR + DPF, pre-SCR) (curated) ↩︎

  4. Curated DTC seed — 6.7 Cummins (EGR + DPF, pre-SCR) (curated) ↩︎

  5. Curated DTC seed — 6.7 Cummins (EGR + DPF, pre-SCR) (curated) ↩︎

Watch a repair

Third-party videos, not ours — for illustration. Confirm anything against the factory service information for your truck.

2017-2020 Super Duty 6.7 Powerstroke Code P2002 Fix. WITH PARTS LIST #newtoyou #powerstroke — Bearded Ford Tech · 6K views

2015 Ford 6.7 Powerstroke Turbo Diesel P2002 DPF Code Comeback!! — Drews Shop Life · 4K views

Ford Code P2002 Explained | Why Your DPF Might Be Cracked (TSB 21-2332) — Fixbook · 4K views