P2002 — DPF Efficiency Below Threshold
The engine ECU has compared pressure and temperature readings across the DPF and concluded the filter is no longer trapping particulates efficiently. It means the system's numbers don't add up — not automatically that the filter is dead.
What commonly causes it
- ·Genuine soot/ash overload after years of service or short-journey use
- ·Differential-pressure sensor or split/blocked sensor hoses giving false readings
- ·Exhaust leaks upstream of the rear pressure take-off skewing the comparison
- ·A previous 'gutted' or failed repair leaving the substrate compromised
Test this before blaming the DPF
- ·Live differential-pressure reading at idle and 2,500rpm — compare against expected values, not just the fault code
- ·Inspect both pressure hoses for splits, kinks and blockage before condemning anything
- ·Check for exhaust leaks around clamps and flexis near the DPF
Will cleaning fix it?
If the substrate is intact and the cause is soot/ash loading, off-car cleaning restores efficiency and clears P2002 after adaptation reset. If the core is cracked, melted or has been tampered with, cleaning cannot fix it — we inspect first and tell you.
Engines this disproportionately affects
Check your vehicle & get a quote
Enter your registration — we'll identify the exact unit and give you the correct recommendation for this fault.
Vehicle data from the DVSA MOT history service. We confirm the exact unit on inspection. Privacy
Test evidence
Every unit is flow- and pressure-tested before and after cleaning. You get the readings, photo evidence and a completion certificate with the unit — proof for you and your customer, not marketing numbers.