P242F — Diesel Particulate Filter Restriction - Ash Accumulation — 6.7 Powerstroke
Diagnostic reference for P242F on 6.7 Powerstroke (2011–present).
What it means
P242F indicates the DPF ash load has reached its service limit on the 6.7L Power Stroke. On this platform the DPF needs cleaning or replacement once ash reaches the limit; excess oil consumption speeds it up.1
Most likely causes
- Ash-loaded DPF at service limit — The DPF ash mass has accumulated to the calibrated service limit, raising backpressure and triggering P242F.1
- Excess engine oil consumption feeding ash — Worn components or oil-related issues increase oil consumption, which raises ash accumulation rate in the DPF.1
- DPF physically restricted or damaged — A cracked or internally restricted DPF can mimic ash-load restriction and contribute to efficiency faults.2
- DPF differential-pressure sensor or sample tubes fault — A faulty pressure sensor, plugged sample tubes, or wiring/connector issues can skew ash-load calculations.3
- Frequent or incomplete regenerations increasing soot load — Repeated interrupted regenerations or excess soot raise overall DPF loading and can mask or accompany ash issues.4
- Excess soot generation from engine faults — Injector, EGR, turbo, or air-leak faults increase soot production, leading to more frequent regenerations and faster ash buildup.5
How to diagnose
- Verify freeze-frame and confirm P242F is present with no other active DPF-related codes.
- Check DPF ash-load parameter with a scan tool; compare to service limit for the 6.7L Power Stroke.
- Inspect DPF differential-pressure sensor readings at idle and elevated engine speed; look for implausible values.
- Inspect pressure sensor sample tubes for blockage, moisture, or damage; verify secure connections.
- Review recent regeneration history and frequency; note any incomplete or aborted regenerations.
- Assess engine oil consumption and look for signs of oil entering the exhaust (blow-by, turbo seal, injector cup).
- Perform a visual and endoscopic inspection of the DPF for cracks, melting, or physical restriction.
- If ash load is at or above service limit and no sensor/tube faults are found, plan DPF removal for professional cleaning or replacement per OEM guidance.
Common mistake to avoid
Cleaning or replacing the DPF before checking its pressure sensor and tubes. Cracked, melted, plugged or wet sensor tubes, or a failing sensor, can set DPF codes while the filter itself is fine. They are cheap to check; clear and verify them before touching the filter. Source: FleetRabbit — P2002 DPF efficiency code causes and fixes.
Parts and tools you may need
- Diagnostic scan tool with Ford/6.7 Powerstroke DPF data support
- Digital multimeter
- Borescope/endoscope
- DPF pressure test kit
- OEM service information for ash-load limits and cleaning procedures
Tools you’ll need
- OBD-II scan tool — Reads DPF ash load parameter and differential-pressure sensor data to confirm P242F and compare to service limit.
- Digital multimeter — Checks DPF differential-pressure sensor supply, ground, and signal voltages for implausible readings.
- Borescope — Allows visual inspection of DPF substrate for cracks, melting, or physical restriction without removal.
- Manometer — Measures actual exhaust backpressure to verify restriction when ash load is at service limit.
Rough cost and difficulty
| Likely repair | Parts | Shop labor | Who usually does it |
|---|---|---|---|
| Internal engine repair (cost depends on teardown findings) | Depends on findings | Depends on findings | Shop |
| Scan-tool forced (parked) regeneration | — | 0.5–1.5 hrs | DIY with tools and a manual |
| DPF differential pressure sensor | $80–$300 | 0.5–1.5 hrs | Easy DIY |
| DPF professional cleaning (bake and blow) | $300–$700 | 1–3 hrs | Shop |
Typical US independent-shop figures; labor runs about $120–$180 per hour (dealers charge more). Confirm the diagnosis before buying parts.
When to see a pro
If the DPF requires removal, cleaning, or replacement, or if high-pressure fuel systems are suspected as the source of excess oil consumption, have a qualified diesel technician perform the work. Do not service high-pressure fuel injection components without proper training and safety equipment.
Check for recalls
Recalls are tied to your truck’s VIN, so check yours directly: enter the VIN at NHTSA’s recall lookup. Open safety recalls are repaired free at a dealer.
Sources
Repair videos: P242F on the 6.7 Power Stroke
Third-party videos, not ours — picked for this engine. Confirm anything against the factory service information for your truck.
Spotted an error, or something missing? Tell us
Run a 6.7 Powerstroke? This goes straight to the editor — it is not published.