Updated August 2025 — by Gianni Tritella. Error code P2002 : Diesel particulate filter (DPF) efficiency below threshold. Symptoms, causes, diagnosis, and professional solutions with cost estimates.
📋 Article Index
Updated 08/19/2025 • Based on workshop diagnoses and OEM technical bulletins
✅ Introduction
The P2002 error code indicates that the efficiency of the diesel particulate filter (DPF) has dropped below the threshold set by the control unit. It is common on diesel vehicles used primarily in urban areas. Ignoring it can lead to DPF clogging, high fuel consumption, decreased performance, and possible engine damage .
Read Also: Diesel Particle Filter (DPF) Problems: Causes, Symptoms, and Solutions in 2025
⚠ Symptoms of P2002 code
- Frequent or incomplete regenerations
- Radiator fan active even after engine stop
- Increased fuel consumption and strong exhaust odor
- Performance drop , engine/DPF lights on
🧪 Quick diagnosis (10 minutes)
- OBD Scanner : Confirm P2002, check other DTCs (temp/pressure sensors, injection).
- Live values : exhaust gas temperature, DPF pressure differential , % soot/soot.
- Check manifold/exhaust for leaks before DPF (gaskets, clamps, cracks).
- Thermal : check that the thermostat brings the engine up to temperature (water/oil).
- Fuel/Oil : Level the oil (beware of possible dilution from regenerations).
🔍 Typical causes
- Urban driving with short journeys → the DPF does not reach the regeneration temperature/time.
- Inaccurate/dirty DPF differential sensor or clogged hoses.
- Thermostat stuck “open” → engine always “cold”.
- Injectors that atomize poorly → excess particulate matter.
- Pre-DPF exhaust leaks → false pressure readings.
🔧 Solutions and interventions
- Testing and cleaning differential sensor tubes + checking temperature sensors.
- Exhaust seal restoration (gaskets/clamps) before DPF.
- Extra-urban drive cycle (20–40 min at constant speed) to facilitate regeneration.
- Forced regeneration in the workshop with diagnosis.
- If severe clogging: DPF bench flush (with before/after backpressure report).
- In extreme cases: DPF replacement with an OEM/approved spare part.
AREXONS 3705 – FAP/DPF CLEANING KIT
Removes residues and encrustations, promotes complete regenerations and lowers system back pressures.
💰 Indicative costs
| Intervention | What's included | Average cost | Time |
|---|---|---|---|
| Forced regeneration | Diagnosis + guided cycle | €100–€180 | 1–2 h |
| DPF wash on the bench | Disassembly, washing, backpressure testing | €250–€400 | 4–8 h |
| Differential sensor | Replacement + adaptation | €120–€220 | 1–2 h |
| Engine thermostat | Replacement + liquid | €150–€280 | 1–3 h |
*Indicative prices excluding VAT; prices vary by brand/model, geographic area, and specific diagnosis.
💡 Prevention & best practices
- Regularly drive outside the city (20–30 min) to promote complete regeneration.
- Check the oil level (possible dilution by diesel) and respect the OEM oil specification .
- Refuel at reputable stations and periodically evaluate professional additives .
- Avoid removing the DPF: an illegal and punishable intervention, with risks for inspections/insurance.
❓ FAQ - Frequently Asked Questions
How long can I drive with P2002 active?
It is best to limit use and intervene promptly: there is a risk of serious blockage , high consumption and related failures.
Does forced regeneration always solve the problem?
No. If the cause is a faulty sensor , a faulty thermostat or worn injectors , the error may return.
DPF flush or replacement?
Bench washing is effective and more economical if the structure is intact. Replacement is necessary when the monolith is damaged.
📌 Conclusions
P2002 is a wake-up call regarding DPF efficiency . With proper diagnosis (sensors, leaks, thermal management) and targeted interventions, premature replacements are avoided and fuel consumption and performance are restored. Rapid action = lower costs and greater reliability over time.
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