What goes wrong
The Denso low-pressure fuel pump, located in the fuel tank, can experience internal component wear or electrical issues, leading to a reduction in fuel pressure delivery. This compromises the engine's ability to receive adequate fuel, especially under load, and can degrade overall performance or prevent the vehicle from starting.
Symptoms to watch for
- Engine cranks but does not start
- Rough idle
- Engine hesitation or sputtering under acceleration
- Check Engine Light (CEL) illuminated with fuel system-related trouble codes (e.g., P0087, P0460)
- Reduced fuel economy
- Engine stalling while driving
Root cause
Premature wear of the internal components of the Denso low-pressure fuel pump, potentially due to manufacturing defects or design limitations, causes a loss of pumping efficiency or intermittent operation.
Permanent fix
- Replacement of the faulty Denso low-pressure fuel pump with an updated OEM or equivalent aftermarket unit. Subaru part number 42021CA000 (superseded part) for the fuel pump assembly.
- Inspect fuel filter and fuel pressure regulator during replacement.
Related recalls / TSBs
FAQ
What causes fuel pump failure (denso)?
Premature wear of the internal components of the Denso low-pressure fuel pump, potentially due to manufacturing defects or design limitations, causes a loss of pumping efficiency or intermittent operation.
How much does it cost to fix?
National average $600–$900.
Is this a DIY repair?
Difficulty 4/5. Replacement of the faulty Denso low-pressure fuel pump with an updated OEM or equivalent aftermarket unit. Subaru part number 42021CA000 (superseded part) for the fuel pump assembly.
What are the symptoms?
Engine cranks but does not start; Rough idle; Engine hesitation or sputtering under acceleration; Check Engine Light (CEL) illuminated with fuel system-related trouble codes (e.g., P0087, P0460); Reduced fuel economy; Engine stalling while driving