P2002
Particulate Filter Efficiency Below Threshold Bank 1
Diesel emissions / DPF
Generic OBD-II
Medium
What it means
P2002 means the diesel particulate filter (DPF) on bank 1 isn't trapping soot as effectively as it should. The engine watches filter efficiency — often through exhaust pressure sensors — and a low reading points to a worn-out, cracked, or poorly regenerating filter, or a pressure sensor reading it wrong. It usually shows up as reduced power and frequent regenerations.
Medium
Can I keep driving? Usually drivable, though you may notice reduced power or forced regeneration; long-term neglect clogs the filter and can require an expensive replacement.
Common symptoms
What you'll notice
- Check-engine light on
- Reduced engine power or limp mode
- Frequent or incomplete regeneration cycles
- Increased exhaust smoke or a sulphur/burning smell
Common causes
Most likely first
- Worn, cracked, or damaged diesel particulate filter (DPF)Likely
- Lots of short, low-speed trips that prevent proper regenerationCommon
- Faulty DPF differential-pressure sensor or clogged sensor linesCommon
- Air or exhaust leak upstream of the filterLess often
- Poor-quality or high-sulphur fuelLess often
- Faulty ECU (rare)Less often
How to diagnose & fix
Work through it in order
- Scan freeze-frame and check for accompanying DPF pressure-sensor or regeneration codes.
- Inspect the DPF and exhaust for leaks, cracks, or physical damage.
- Test the DPF differential-pressure sensor and its hoses.
- If the filter is loaded but serviceable, run a forced regeneration or take an extended highway drive.
- Replace or professionally clean the DPF if it's beyond regeneration; clear and re-test.
FAQ
Quick answers
Is it safe to drive with P2002?+
Short-term, usually yes, but the car may lose power or force regeneration cycles. Ignoring it lets soot build up until the filter needs replacing.
Can I just clear P2002?+
Clearing it won't restore a clogged or damaged filter — the code returns once the DPF's efficiency is measured again. Address the filter or sensor cause.
Related codes
Often seen with P2002
Read & clear P2002 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX