P2002: Diesel Particulate Filter Efficiency Below Threshold (Bank 1)

What does P2002 mean?

The bank 1 diesel particulate filter is not meeting the expected filtering-efficiency check. This is not simply a command to regenerate: a damaged filter, exhaust leak, or incorrect sensor feedback can also cause the result.

Generic OBD-II definition: Diesel Particulate Filter Efficiency Below Threshold (Bank 1). Confirm applicability in your vehicle service information.

Common causes

• Damaged or ineffective DPF
• Failed regeneration or heavy soot loading
• Exhaust leak or faulty pressure-sensor feedback

Symptoms

• Check engine or DPF light
• Reduced power
• More frequent regeneration or worse economy

Diagnostic focus

Do not prescribe a forced regeneration from this code alone. High soot load, engine faults, diluted oil, or a damaged filter can make regeneration ineffective or unsafe. Never remove emissions equipment.

Can I keep driving with P2002?

Severity: Medium Follow the owner's manual for DPF warnings. Avoid continued operation with severe power loss, overheating, or an oil level rising from fuel dilution; seek diesel-system diagnosis.

If the check engine light is flashing or the car runs badly, stop driving and have it checked.

Typical fixes

• Inspect exhaust sealing and sensor plumbing
• Review soot/pressure and regeneration data with a diesel-capable tool
• Follow the vehicle-specific DPF diagnostic and service procedure

Sources & review

• OBD-Codes.com: P2002
• TroubleCodes.net: P2 code definitions

Definitions and diagnostic background checked 2026-11-06. Generic guidance, not a substitute for the service procedure for your exact year, engine, and transmission.