P0191
Fuel Rail Pressure Sensor Circuit Range/Performance Bank 1
Fuel & air metering (fuel delivery)
Generic OBD-II
High
What it means
P0191 means the fuel rail pressure sensor is giving a reading that doesn't match what the engine control module expects. The ECM uses that value to regulate fuel pressure, so an inaccurate signal — whether the sensor is faulty or the actual pressure is off — can cause hesitation, stalling, hard starting, and sometimes limp mode until it's diagnosed.
High
Can I keep driving? Be cautious — because fuel pressure is controlled from this sensor, the engine can hesitate, stall, or start hard, and may drop into limp mode. Diagnose promptly.
Common symptoms
What you'll notice
- Check-engine light on
- Hesitation, surging, or reduced power (possible limp mode)
- Hard starting or occasional stalling
- Poor fuel economy
Common causes
Most likely first
- Failed or drifting fuel rail pressure sensorLikely
- Wiring or connector fault in the sensor circuitCommon
- A genuine fuel-pressure problem (weak pump or regulator) the sensor is reportingCommon
- Poor sensor ground or reference-voltage faultLess often
- Failed engine control module (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and compare the sensor's pressure reading against a mechanical gauge if possible.
- Inspect the sensor connector and wiring for damage, corrosion, or a poor ground.
- Verify the sensor's reference voltage and signal are within spec.
- If actual fuel pressure is out of range, diagnose the pump and pressure regulator; if only the signal is wrong, replace the sensor.
- Clear the code and road-test to confirm it stays off.
FAQ
Quick answers
Is it safe to drive with P0191?+
Drive cautiously. The ECM regulates fuel pressure from this signal, so a bad reading can cause stalling or limp mode — get it checked before relying on the car.
Can I just clear P0191?+
It returns quickly unless the sensor, its wiring, or an underlying fuel-pressure problem is repaired.
Related codes
Often seen with P0191
Read & clear P0191 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX