P2002: Diesel Particulate Filter Efficiency Below Threshold (Bank 1)
The diesel particulate filter on bank 1 is not trapping soot as it should.
Normal risk
Safe to drive. Emissions are higher.
Short answer · Can I keep driving with P2002?
Yes. Emissions are higher and the car may fail an inspection. Have the filter and sensor checked.
What does P2002 mean?
Code P2002 means the engine control unit estimates the particulate filter is not filtering correctly. This can be a damaged filter or a sensor problem.
A cracked filter or a removed filter cannot trap soot. A faulty pressure sensor or split hose can give the same reading.
The filter efficiency is calculated from the differential pressure, so a sensor fault or a split hose must be ruled out first.
What the car does when the code is set
The particulate filter or check engine light comes on. The car usually drives normally, but emissions of soot are higher. On some cars regeneration is suspended.
How the system works
A diesel particulate filter traps soot from the exhaust in a ceramic honeycomb with closed channels. The soot is burnt off at intervals by raising the exhaust temperature, a process called regeneration. A differential pressure sensor measures the pressure before and after the filter: a full filter gives a high difference, a damaged or empty filter almost none. If the pressure difference is too low for the exhaust flow, the engine control unit concludes the filter is no longer working.
Common symptoms
Possible causes
Listed without ranking. The cause on your car depends on make, engine and mileage — see the maker notes below.
- Damaged or cracked particulate filterThe filter no longer traps soot.
- Removed or tampered filterAn emptied filter is detected.
- Faulty differential pressure sensorThe sensor misreads the pressure across the filter.
- Leaking sensor hosesSplit hoses to the pressure sensor.
How it is diagnosed
- Check the sensor hosesInspect the hoses from the filter to the pressure sensor for splits and correct connection.
- Check the pressure readingWith the engine off, the differential pressure should read near zero.
- Look for soot at the tailpipeBlack soot inside the tailpipe after a clean suggests a damaged filter.
- Have the filter inspectedA workshop checks the filter for cracks.
Questions about P2002
Can a removed filter set P2002?
Yes. Emptied or removed filters typically set this code. Driving without a working filter is illegal for road use in most countries.
Can I see soot at the tailpipe?
A clean tailpipe that turns black soon after cleaning suggests the filter is damaged.
Is removing the particulate filter allowed?
No. Removing the filter is illegal for road use in most countries and fails inspections.
Can a pressure sensor fault cause this code?
Yes. Always check the sensor and hoses before replacing the filter.