A diesel particulate filter (DPF) traps soot and burns it off through regeneration. When the DPF clogs faster than it can regenerate, you get reduced power, more frequent regen cycles, and eventually a P2002 fault code followed by limp mode. Catching it early often means a $300 cleaning instead of a $3,000 replacement.
A clogged DPF caught at 60-70% soot load can be off-vehicle bake-cleaned for $300-$700. A DPF that's baked itself into a melted mass needs full replacement at $2,000-$4,000.
When soot load exceeds the safety threshold, the ECM cuts boost and fuel to limit further damage. You'll feel sluggish acceleration and a wrench or DPF light on the dash. Code P2002 or P244A.
View P2002 Diagnosis →Healthy DPF regen runs every 300-700 miles. A failing DPF tries to regen every 30-100 miles and often doesn't finish. Watch your fuel economy drop noticeably during these cycles.
Get a free diagnosis →A clogged DPF runs much hotter during regen attempts. You'll smell burning and the exhaust pipe will glow. Risk of grass fires if parked over dry vegetation.
Get a free diagnosis →Active regen uses extra fuel through post-injection. Frequent failed regens can drop MPG by 15-25%.
Get a free diagnosis →Severe DPF backpressure leans out the cylinders, makes the turbo work harder, and produces hard cold starts and rough idle.
Get a free diagnosis →Black smoke under load = soot blow-through past a damaged DPF. White smoke during regen = unburned fuel from a failed regen cycle.
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Ford TSB 19-2356 covers DPF replacement criteria on 6.7L Powerstroke. GM TSB 16-NA-377 addresses Duramax DPF cleaning before replacement. Ram TSB 18-100-19 covers 6.7L Cummins DPF replacement under emissions warranty. EPA emissions warranty covers DPF for 8 years / 80,000 miles federal, 7 years / 70,000 miles in California - always check before paying out of pocket.
If you see a check engine light, these codes most often relate to the issues above. Click any code for full diagnosis steps.
100,000-200,000 miles on highway-duty diesels. Stop-and-go and short-trip use can cut that in half.
No - the bake cleaning process requires 600°C+ industrial ovens. Off-vehicle cleaning costs $300-$700 at a specialty shop.
It's illegal under the Clean Air Act, voids warranty, and stops emissions registration in most states. Don't.
Some fuel-borne catalysts (Cerium-based) help slightly. They cannot remove a heavily clogged DPF - only assist regen on a borderline filter.
Cleaning ($300-$700) bakes existing soot and ash out. Replacement ($2,000-$4,000) is required when the substrate is cracked or melted.
A scan tool reads DPF soot load %, ash load %, and miles since last regen. >80% soot load means it's past the point of self-regen.