Hello can anyone tell me what trouble code PO191 - Fuel Rail Pressure Sensor means and what do I need to do?

Hey, did you find an answer to the PO191 code? A Ford Focus with same problem, let me know if you find out. Thanks!

First thing would probably be to check your fuel pressure, somewhere between 20 and 60 psi with engine running,, if not, then you'll have to dive in deeper to find out what's going on, could be the sensor itself, or any of the various parts of the fuel system.

P0191 - Fuel Rail Pressure Sensor Circuit Performance (FRP).

DESCRIPTION: The comprehensive component monitor (CCM) monitors the FRP pressure for acceptable fuel pressure. The test fails when the fuel pressure falls below or exceeds a minimum/maximum calibrated value for a calibrated period of time.

POSSIBLE CAUSES:
High fuel pressure.
Low fuel pressure.
Damaged FRP sensor.
Excessive resistance in circuit.
Low or no fuel.

DIAGNOSTIC AIDES: A FRP PID value during KOER of 138 kpa (20 psi) and 413 kpa (60 psi) for gasoline or 586 kpa (85 psi) and 725 kpa (105 psi) for natural gas vehicles (NG) is acceptable.

If you'd like a PDF of the full factory troubleshooting guide for this code, send me a private message with an e-mail address for you that can accept PDF files and a quick description of the request to refresh my memory.

-Rod

I am getting the same code. My engine is the 3.0L(2)FFV with 100,000 miles. Someone has already replaced the DPFE sensor. If the engine starts for me, it may idle fine, or it may miss and stall. While running, if the accelerator pedal is depressed too quickly, the engine tries to stall.( Same symptom as a TPS.) I can depress the pedal slowly and the engine revs smoothly. I am getting P0191, P1237, and P0193 codes. Please help.

The P1237 code is "Fuel Pump Secondary Circuit Malfunction" which indicates that the FPDM has detected a fuel pump secondary circuit fault according the to the factory service manual. This is likely due to:
-Open or shorted fuel pump power circuit
-Open fuel pump return circuit to Fuel Pump Driver Module (FPDM)
-Open or shorted circuit in the fuel pump
-Locked fuel pump rotor
-Damaged FPDM

The P0191 is "Fuel Rail Pressure (FRP) Sensor Circuit Performance" and possibly means:
-High fuel pressure
-Low fuel pressure
-Damaged FRP sensor
-Excessive resistance in circuit
-Low or no fuel

The P0193 is "Fuel Rail Pressure Sensor Circuit High Input" and could be caused by:
-FRP signal shorted to VREF or VPWR
-RFP signal open
-Damaged FRP sensor
-Damaged PCM


The common item to check for all three of these codes is fuel pressure. Let's start there.

Also, when was the last time the fuel filter was replaced, and how often do you use fuel injector cleaner?

-Rod

The filter was replaced less than 8 months ago. Never have cleaned the injectors. I am thinking the fuel pump is through. I got the engine to start yesterday and I noticed a whining noise coming from the rear of the car. The noise is not constant. I was told the noise is probably the fuel pump bearing. Does this sound right? I am hoping not figuring a replacement will cost no less than $200 just for the part.

Yeah, with this information the fuel pump is highly suspect. If your Taurus is not the flexible fuel version, you can probably find a replacement fuel pump for less than $200.

-Rod