P0191
Medium SeverityFuel Rail Pressure Sensor Circuit Range/Performance
Fuel System
P0191 — Instant Answer
Fuel Rail Pressure Sensor Circuit Range/Performance
Severity: MEDIUM SEVERITY
Meaning: The fuel rail pressure sensor reading does not match expected values. Usually a sensor fault or wiring issue.
Safe to drive? Usually yes with caution, but confirm root cause before long trips.
Estimated repair cost: $30 - $80
Most common causes:
- 1. Faulty fuel rail pressure sensor (35-45% of cases)
- 2. Wiring issue (10-25% of cases)
- 3. Actual fuel pressure problem (10-25% of cases)
Symptoms
- ⚠️Engine performance issues
- ⚠️Hard starting
- ⚠️Stalling
- ⚠️Check engine light
Related Symptoms
Common Causes
How to Diagnose P0191
- 1Check sensor wiring
- 2Compare sensor reading to mechanical gauge
- 3Test fuel pump pressure
- 4Replace sensor if readings incorrect
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Repair guides, symptom pages, and wiring diagrams related to P0191.
Related Codes
Fuel rail pressure sensor reads too low. Could be a sensor fault or actually low fuel pressure.
Fuel rail pressure sensor reads higher than expected.
The engine is running lean on bank 1 — too much air or not enough fuel. The ECM has maxed out its fuel trim trying to compensate. Common causes include vacuum leaks and dirty MAF sensors.
Frequently Asked Questions
- What does the fuel rail pressure sensor do?
- It monitors fuel pressure in the fuel rail so the ECM can adjust injector pulse width for proper fuel delivery.
- Is this sensor easy to replace?
- Usually yes — it screws into the fuel rail. Relieve fuel pressure first and have a rag ready for fuel spillage.
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Author & Review
Written by AllOEMManuals Editorial Team. Reviewed by ASE-certified technicians and updated with factory-reference checks for fitment-sensitive steps.
This guide was drafted with AI assistance and reviewed for accuracy by a human editor.
Last updated: 2026-05-07