Fuel psi low - 1995 Oldsmobile Ninety Eight Regency

the pressure should be around 60 psi
if not it may be a faulty pressure regulator in the fuel manifold

P0191 - Fuel Rail Pressure Sensor Circuit Performance (FRP) 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. High fuel pressure.
Low fuel pressure.
Damaged FRP sensor.
Excessive resistance in circuit.
Low or no fuel.
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. You will have to check these items to find the cause of the code. no short cuts.

the spec. is 41-47 psi at idle
http://www.ericthecarguy.com/forum/8-Service-and-Repair-Questions-Answered-Here/25682-2002-cadillac-deville-possible
fuel-pump-failure

Your fuel pressure at 269 kpa is equal to 35 psi your fuel oressure is to low you need to have 448 kpa or 65 psi. Kpa is a metric measurement liqud pressure.

Fuel pressure too low. looks like you have a weak fuel pump. here is the fuel pressure spec

Turn ON the ignition leaving the engine OFF, the fuel pressure should be 415-455 kPa (60-66 psi) when the pump is running

ok now check fuel psi if the car dont the proper fuel psi that can happen if so and not two low change fuel filter.still a promblem check the fuel pump relay if that is good drop tank replace fuel pump.that if is you do not have proper fuel psi not even 1 pound off go to autozone.com to c ur fuel psi amout.b.c. you gave no motor size and last 8 vin or made date .goodlucj

40.5 psi to 47.0 psi
wiyh engine off , ignition on and fuel pump running
fuel system pressure with engine running at idle will be low at 40.5 give or take 2 to 3 psi meaning 40.5 plus 3 psi more or 40.5 to 3 psi less

I would change the fuel pressure regulator first, if no change in pressure the fuel pump is on the way out.I have a 01 silverado 4.8 and my fuel pressure is between 55and60 psi.

I WOULD CHECK FUEL PRESSURE.IT SHOULD BE 55 PSI FOR THE 3.3 ENGINE.48 PSI FOR THE 3.5 ENGINE.THIS TEST YOU HAVE TO DISCONNECT VACUUM HOSE FROM FUEL PRESSURE REGULATOR.IF FUEL PRESSURE IS LOW.REPLACE FUEL FILTER.IF STILL LOW REPLACE FUEL PUMP.

try the fuel pressure regulator