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P2002 – Particulate Filter Efficiency Below Threshold – HDi FAP with Additive (Eolys) (Peugeot / Citroën / DS 1.6 HDi)

Fault code P2002 means "Particulate Filter Efficiency Below Threshold – HDi FAP with Additive (Eolys)". It is common on 1.6 HDi (DV6 – 9HX, 9HY, 9HZ, 9HR), 2.0 HDi / 2.2 HDi (DW10, DW12), Early 1.6 BlueHDi with additive system engines. Below are the real-world causes, step-by-step tests and OEM part numbers.

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P2002 quick summary

Fault codeP2002
MeaningParticulate Filter Efficiency Below Threshold – HDi FAP with Additive (Eolys)
SystemPowertrain (Engine & Transmission)
VehiclesPeugeot / Citroën / DS (Stellantis)
Common on1.6 HDi (DV6 – 9HX, 9HY, 9HZ, 9HR), 2.0 HDi / 2.2 HDi (DW10, DW12), Early 1.6 BlueHDi with additive system
SeverityMedium
Can I drive?Yes, for a short time. If the filter keeps clogging the car goes into limp mode and fuel consumption rises – have it checked soon.
Repair cost€60 – €2,000

Symptoms of P2002

  • Message 'Risk of particle filter blocking' or 'Particle filter: see handbook'
  • Check Engine / anti-pollution warning light
  • Loss of power, limp mode
  • Regenerations become frequent (fan running after switch-off, higher idle)
  • More smoke, smell of soot

Most common causes of P2002 (most likely first)

Mechanic's Pro Tip

Unlike most diesels, PSA's FAP filter needs an additive (Eolys / Powerflex) that is dosed into the fuel tank to help the soot burn at a lower temperature. When the additive bag runs empty, or the pump stops dosing, the filter clogs quickly. So on a Peugeot or Citroën HDi, check the additive level and dosing system BEFORE you condemn the filter. Use only the additive generation specified for your car and reset the additive counter after refilling.

  1. 1.Additive (Eolys / Powerflex) tank empty or counter not reset after refilling

    Most likely

  2. 2.Faulty additive pump, injector or wiring – no dosing

  3. 3.Interrupted regenerations from short trips

  4. 4.Faulty differential pressure sensor or cracked sensor pipes

  5. 5.Filter full of ash at end of life

Step-by-step diagnostic guide

  1. 1

    Read all codes with DiagBox or a PSA-capable scanner; note any manufacturer-specific additive codes alongside P2002.

  2. 2

    In live data check the remaining additive quantity and the filter loading (soot mass and differential pressure).

  3. 3

    Run the additive pump actuator test and look for leaks or a blocked line at the tank.

  4. 4

    Check the differential pressure sensor and its hoses for cracks or blockage.

  5. 5

    Refill with the correct additive, prime the system, reset the counter, then run a forced regeneration with the tester. If the back pressure stays high, the filter must be cleaned or replaced.

Frequently asked questions

How often does the FAP additive need refilling?

It depends on the system generation – roughly every 80,000 to 180,000 km. The car warns when the level is low. The correct additive type (e.g. Eolys 176 or Powerflex / DPX42) is not interchangeable, so check it by VIN.

How much does it cost to fix P2002 on a Peugeot / Citroën HDi?

An additive refill with reset typically costs about 60–150 €. A new additive pump or bag tank costs a few hundred euros. Professional filter cleaning costs several hundred euros, and a new filter roughly 800–2,000 € fitted depending on the model.

Related fault codes

This guide is for information only. Working on vehicles can be dangerous — if you are unsure, have the car checked by a qualified mechanic. Values can differ between model years; always check the manufacturer's repair information.