OBD codes / P0148
P0148
SeriousFuel Delivery Error
Take P0148 more seriously than an O2 sensor code. A genuine fuel-delivery shortfall can mean stumbling, power loss, or stalling — potentially at highway speed — and on diesels, running a starving high-pressure pump can damage it. If the engine is running noticeably poorly, have it towed or drive only as far as the shop; if it runs normally, get it diagnosed promptly anyway.
What this code means
Despite sitting among the oxygen-sensor codes numerically, P0148 is a fuel-system fault: the computer has detected that actual fuel delivery does not match what it commanded — a mismatch between expected and measured fuel pressure or volume. It appears most often on diesel and other high-pressure injection systems, where the computer tracks fuel pressure closely. Possible causes span the whole supply path: a weak lift or high-pressure pump, a restricted fuel filter, air entering the fuel supply, a leaking or stuck pressure regulator, worn injectors returning too much fuel, or in some cases a faulty pressure sensor misreporting the situation. Because the causes and labor vary enormously by fuel-system design, this code needs a proper vehicle-specific diagnosis — fuel pressure tests, leak-down checks — rather than a guessed part.
Symptoms you might notice
- Hard starting or long cranking
- Loss of power, especially under load or at higher RPM
- Engine stumble, surging, or stalling
- Check-engine light, possibly with reduced-power mode
- Rough running that worsens as demand rises
What it costs to fix
Varies by vehicle — get it diagnosed.
The repair cost for this code depends too much on your exact vehicle and the underlying cause to quote a meaningful range. Confirm the cause first so you only pay for the fix you actually need.
Diagnose P0148 for my vehicle →Frequently asked
Is P0148 an oxygen sensor code?
No — the number sits in the O2 range, but it is a fuel-system fault: measured fuel delivery does not match what the computer commanded. Diagnosis focuses on pumps, filters, pressure regulators, and injectors, not exhaust sensors.
Can I drive with P0148?
With caution, and not far. Fuel-delivery faults can cause sudden power loss or stalling, and continuing to run some systems (especially diesel high-pressure pumps) with inadequate supply risks expensive secondary damage. Get it diagnosed before regular driving.
What gets checked first for P0148?
Fuel pressure, measured against your vehicle's specification at idle and under load, plus the filter and any companion codes. That one test usually splits the problem into supply side (pump, filter, air leak) versus control side (regulator, sensor, injectors).
Why can't I get a cost estimate for P0148?
Because the fix ranges from a fuel filter to a high-pressure pump, and fuel-system designs differ enormously between vehicles — no honest single range covers it. A diagnosis pinning down the failed component is what makes a real estimate possible.
Seeing P0148 on your car? Get a diagnosis specific to your exact year, make and model.
Diagnose P0148 for my vehicleRelated trouble codes
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Generic OBD-II reference. Manufacturer-specific behavior varies — confirm with a scan tool and, for safety-related codes, a professional inspection.