DTC code
P0191
Fuel Rail Pressure Sensor Circuit Range/Performance Bank 1
Technical guide
Symptoms
- Rough idle
- hesitation
- power loss
- possible no-start
Probable causes
- Fuel rail pressure sensor range/performance
- erratic sensor reading
- HPFP wear causing pressure fluctuation
- wiring issue
Diagnostic steps
- Read live fuel pressure vs target.
- Check FRP sensor connector.
- Compare actual pressure with expected.
- Replace sensor if erratic.
- Check HPFP if pressure genuinely erratic.
Brand-specific notes (Opel/Vauxhall)
Opel/Vauxhall · Astra/Vectra/Zafira · 1.9 CDTi Z19DTH
Symptoms
- Rough idle
- loss of power
- hard starting
- black smoke
- engine may cut out
Probable causes
- Faulty fuel rail pressure sensor
- wiring fault to sensor
- fuel pressure regulator on HPFP worn
- air in high pressure fuel system
Diagnostic steps
- Check fuel rail pressure sensor connector and wiring.
- Read live fuel pressure data.
- Compare actual vs target pressure.
- Replace FRP sensor if reading erratic.
- If pressure genuinely low - check HPFP and regulator.
Cross-checked technical synthesis (QA). It does not replace the manufacturer's procedure.
Models most reported with this code (NHTSA)
Count of distinct owner complaints mentioning the code. US data — same engines, same failures.
AI here is a librarian: this page shows only what mechanics confirmed, or says “unknown”. It never suggests a diagnosis — MECCANIC interprets the code, never your car.
0 confirmed cases on P0191
Nothing confirmed yet for this code. No guess is offered on purpose.
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