Emission Control (Diesel)

P2002Diesel Particulate Filter Efficiency Below Threshold (Bank 1)

High RiskDifficulty:Moderate1 hour-1 day
Is it safe to drive?
Short trips, with care

May go into limp mode. If the DPF is clogged, exhaust back pressure rises and the turbo and engine are strained. Constant short trips make it worse.

Will it pass inspection?
Risky

A car with a punctured or deleted DPF may fail the smoke test. Deleting the DPF is illegal.

01 / 06

What does P2002 mean?

The particulate filter is either clogged or, the opposite, punctured/cracked; the ECU sees that the filter isn't doing its job. Using a diesel only in the city interrupts regenerations and the filter fills with soot. Don't pay for a filter before checking the differential pressure sensor and its hoses.

The ECU monitors the differential pressure between the DPF inlet and outlet. If it falls outside the expected model (too low: hole/crack, too high: blockage), P2002 is stored. A faulty differential pressure sensor or a cracked sensor hose can also trigger this code.

02 / 06

How to fix P2002

Steps are ordered from cheapest to most expensive. If a step doesn't solve it, move to the next one, and don't let a garage replace parts blindly.

  1. 1

    Check the differential pressure sensor hoses

    DIY

    A cracked or reversed hose can make a healthy DPF look faulty.

  2. 2

    Read soot/ash values

    Pro job

    Diagnostics show DPF load, time since last regeneration and differential pressure.

  3. 3

    Motorway driving or a service regeneration

    Pro job

    First try with active driving; if that fails, a forced regeneration is done with a diagnostic tool.

  4. 4

    Replace the differential pressure sensor

    Pro job

    If the sensor doesn't read close to zero with the engine off, it is faulty.

  5. 5

    DPF cleaning (removed)

    Pro job

    It is washed/baked by machine; the ash is cleaned out too.

  6. 6

    DPF replacement

    Pro job

    Replaced if the filter is cracked or cleaning doesn't help.

Don't replace these first

  • DPF (without checking the sensor)
  • Turbocharger

These parts are often replaced unnecessarily for P2002. Don't spend money on them before doing the checks above.

03 / 06

P2002 symptoms

  • DPF warning light / check engine light
  • Loss of power, limp mode
  • Fan running constantly (regeneration attempts)
  • Higher fuel consumption
  • Engine oil level rising (fuel diluting the oil)

04 / 06

What causes P2002?

  • DPF full of soot (interrupted regenerations)High
  • DPF differential pressure sensor / cracked hoseHigh
  • Wrong engine oil (non Low-SAPS oil → ash build-up)Medium
  • Excessive soot from EGR or injectorsMedium
  • Punctured / cracked DPFLow

05 / 06

Which cars commonly get P2002?

06 / 06

Frequently asked questions

What does fault code P2002 mean?

P2002 stands for “Diesel Particulate Filter Efficiency Below Threshold (Bank 1)”. The particulate filter is either clogged or, the opposite, punctured/cracked; the ECU sees that the filter isn't doing its job. Using a diesel only in the city interrupts regenerations and the filter fills with soot. Don't pay for a filter before checking the differential pressure sensor and its hoses.

Can I drive with code P2002?

Short trips, with care. May go into limp mode. If the DPF is clogged, exhaust back pressure rises and the turbo and engine are strained. Constant short trips make it worse.

Will a car with code P2002 pass vehicle inspection?

Risky. A car with a punctured or deleted DPF may fail the smoke test. Deleting the DPF is illegal.

Can a car with a DPF be used only in the city?

It can, but at least 20-30 minutes of motorway driving once a week is recommended. Otherwise regenerations get interrupted and the filter clogs.

Which oil should be used with a DPF?

The low-ash (Low-SAPS) oil specified by the manufacturer, for Renault an RN0720-approved oil. The wrong oil causes permanent ash build-up in the DPF.

Related codes

P0401P0299P0101