P2002 on Mazda: How to Diagnose & Fix
Diesel Particulate Filter Efficiency Below Threshold (Bank 1)
1 Mazda model · 1 documented issue
P2002 on Mazda by model: symptoms, diagnosis and fix
3.3L diesel CX-60 owners report the diesel particulate filter (DPF) entering active regeneration very often, particularly on short/urban journeys where the exhaust never reaches full temperature. During a regen the engine injects extra fuel to burn off soot, driving instantaneous consumption up to ~15-17 L/100km and dropping average economy to the mid-20s mpg. Owners who do mostly short trips risk incomplete regens, a partially clogged DPF, and eventually a limp-mode/emissions warning. Mazda advises a periodic 30-45 minute higher-speed drive to complete a regen.
Common Symptoms
- Frequent DPF regeneration cycles
- Sudden drop in fuel economy to mid-20s mpg
- Higher idle/cooling-fan running after stopping
- Diesel smell after short trips
- DPF or emissions warning light on short-journey use
How to Fix
For short-trip drivers, complete an uninterrupted 30-45 minute motorway drive every 2-3 weeks to allow a full passive/active regen. If a DPF warning appears, have the dealer run a forced/service regeneration and inspect for related Denso injector spray-pattern issues. A heavily loaded DPF that will not regen may require professional cleaning or replacement.
Sources for this issue (1)
P2002 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P2002 mean on a Mazda?
P2002 stands for "Diesel Particulate Filter Efficiency Below Threshold (Bank 1)." P2002 indicates that the diesel particulate filter (DPF) on bank 1 is performing below its required efficiency threshold. The DPF captures and stores soot from diesel exhaust and periodically burns it off (regeneration); the engine computer monitors exhaust pressure across the filter and other data to judge how well it's trapping and clearing soot. When that efficiency falls too low, this code sets. Symptoms can include reduced power, a clogged-filter warning, frequent or failed regenerations, and increased emissions. On Mazda it is documented across 1 model: CX-60.
What are the most common causes of P2002?
The most common causes of P2002 are: Clogged or damaged diesel particulate filter, Failed or incomplete DPF regeneration (mostly short trips), Faulty differential (DPF) pressure sensor or hoses, Faulty exhaust temperature sensor(s), Exhaust leak before or across the DPF, Engine running issues causing excess soot (injectors, EGR, turbo), Use of incorrect (non-low-ash) engine oil or fuel quality issues. The specific cause varies by vehicle.
How much does it cost to fix P2002 on a Mazda?
Repair costs vary widely with the root cause and Mazda model; each issue on this page carries its own estimate where one is published.
Looking for P2002 on a different make?
View P2002 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.