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System: Powertrain (P-Code) Coverage: SAE Standard (Generic) Fault Family: dpf_efficiency_performance

Code P2002: Particulate Filter Efficiency Below Threshold Bank 1

Diagnostic & Technical Explanation
P2002 (Particulate Filter Efficiency Below Threshold Bank 1) sets when the differential-pressure or soot-model calculation shows the diesel particulate filter is passing more particulate matter than its efficiency threshold allows, or when an abnormal pressure-drop signature indicates a cracked or missing filter substrate. A substrate cracked or melted by an uncontrolled regeneration event, a swapped-in filter that lacks the correct catalytic coating, and a leaking or misrouted differential-pressure sensor hose are the most common causes.

Probability-Ranked Repair Procedures (4 Ranked Fixes)

Rank #1

Inspect DPF differential pressure sensor hoses for cracks or swapped routing

Easy DIY
Parts Estimate: $10.0–$30.0 USD Labor Estimate: 0.6 Shop Hours
  1. 1. Locate the two pressure sensor hoses running to ports ahead of and behind the DPF
  2. 2. Check for melted, kinked, or disconnected hose sections along the exhaust heat shield
  3. 3. Confirm the hoses are routed to the correct ports and not swapped
  4. 4. Reseat the hoses, clear the code, and monitor for its return
Required Replacement Parts: 🔧 High-temperature silicone vacuum hose · 🔧 Hose clamp set
Rank #2

Perform a manual DPF regeneration and inspect soot loading

Moderate DIY
Parts Estimate: $20.0–$60.0 USD Labor Estimate: 1.0 Shop Hours
  1. 1. Connect a scan tool and check the current soot load percentage and DPF status PIDs
  2. 2. Drive at sustained highway speed or command a parked regeneration per the platform procedure
  3. 3. Confirm exhaust back-pressure and soot load fall to the normal range afterward
  4. 4. Recheck efficiency monitor completion
Required Replacement Parts: 🔧 Diesel exhaust fluid (DEF)
Rank #3

Send the DPF out for professional cleaning (ash removal)

Professional Required
Parts Estimate: $250.0–$600.0 USD Labor Estimate: 1.5 Shop Hours
  1. 1. Remove the DPF assembly for inspection outside the vehicle
  2. 2. Deliver it to a DPF cleaning service for pneumatic/thermal ash removal
  3. 3. Weigh or pressure-test the cleaned filter against manufacturer specification before reinstalling
  4. 4. Reinstall with new gaskets and clear the efficiency code
Required Replacement Parts: 🔧 Exhaust gasket and clamp set
Rank #4

Replace the diesel particulate filter assembly

Professional Required
Parts Estimate: $1200.0–$3200.0 USD Labor Estimate: 3.5 Shop Hours
  1. 1. Confirm the filter substrate is physically cracked, melted, or missing via borescope or removal inspection
  2. 2. Remove the DPF housing from the exhaust system, supporting adjacent flex joints
  3. 3. Install the new filter with new gaskets and clamps, torquing to specification
  4. 4. Clear codes and complete the DPF learn/reset procedure required by the platform
Required Replacement Parts: 🔧 Diesel particulate filter assembly · 🔧 Exhaust gasket and clamp set

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