Fuel 01 V6 - 90 psi Fuel Pressure when Hot!! / P0193 Tried everything

A month ago I replaced a failing fuel pump, changed the fuel filter, and the fuel rail pressure sensor. I now have P0193 "Fuel Rail Sensor High Circuit Input". The car runs fine for the most part, and when I turn off the check engine line it runs with 0 issues. I've warrantied the sensor, and the problem remained. My fuel pressure will be at ~36 Key on engine off, and when I start it, especially after I have reset the check engine light, it will be around 40 while running and driving, however once it heats up it gets up around 65, and when my car has the check engine light on and is running at standard operating temp is can be upwards of 90 PSI. my OBD-II reader says that my Catalyst is failing emission test, could a clogged cat be causing my fuel pressure to spike like this? I have tried everything besides working with the Cat, and I don't know what else to do.
 
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A month ago I replaced a failing fuel pump, changed the fuel filter, and the fuel rail pressure sensor. I now have P0193 "Fuel Rail Sensor High Circuit Input". The car runs fine for the most part, and when I turn off the check engine line it runs with 0 issues. I've warrantied the sensor, and the problem remained. My fuel pressure will be at ~36 Key on engine off, and when I start it, especially after I have reset the check engine light, it will be around 40 while running and driving, however once it heats up it gets up around 65, and when my car has the check engine light on and is running at standard operating temp is can be upwards of 90 PSI. my OBD-II reader says that my Catalyst is failing emission test, could a clogged cat be causing my fuel pressure to spike like this? I have tried everything besides working with the Cat, and I don't know what else to do.

No, a clogged catalytic converter will not raise your fuel pressure. You should look into your fuel regulator and see what's going on with that.
 
No, a clogged catalytic converter will not raise your fuel pressure. You should look into your fuel regulator and see what's going on with that.
I replaced the FRPS on the fuel rail twice now, and it did not change the issue at all. And I have tested it by removing the vacuum line and the pressure did slightly increase, so I am pretty sure the sensor itself is fine.
 
Do you have a
I replaced the FRPS on the fuel rail twice now, and it did not change the issue at all. And I have tested it by removing the vacuum line and the pressure did slightly increase, so I am pretty sure the sensor itself is fine.

Do you run a boost referenced fuel regulator or fuel management unit? Is the car boosted?
 
Rog... I'm going to alter your thread title a little bit to help draw the right folks in.
I found this online

"Some returnless systems will actually vary the pump output to emulate a referenced system, or to offer more fuel pressure at higher demands and less fuel pressure at lower demands. Ford fuel systems modulate the pump in an effort to maintain effective fuel pressure at 3 bar. The Corvette ZR1 runs fuel pressure in the 30s until an increased demand is on the system, at which point it will ramp the fuel pressure up to 88psi in the rail. Systems like these use sensors that record the fuel pressure, and when combining that pressure with the manifold pressure, the PCM knows what the effective pressure is and will determine a pulse width for the injector accordingly. Systems like these offer the best of both worlds. "

Now I know its not the same car, but could the 90 PSI be from my system thinking it needs more input? One thing I did notice about my system is that even at just a normal idle and in park, my engine calculated load can be anywhere from 35 to 50%. I've noticed my brothers dodge Durango sits around 5%. Could there be something causing my engine to have a large idle load and the system thinks it needs a lot of fuel.
 
It seems to me that your fuel pump is running flat out. IMO the P0193 is because the PCM is unable to control fuel pressure via the fuel pump driver modular (FPDM). What could cause this? A ground short in the fuel pump return wire is on possibility.

How could this happen? Are you interested in an educated WAG? If so, one possibility is that the fuel pump signal return wire was pinched between the fuel tank and the gas tank hat. It's easy to see how it can happen when stuffing all of the wires inside while attempting to compress the gas tank hat.

One might be asking how it's possible for a wire to be grounded but not blow a fuse. It would blow a fuse IF the positive supply wire were grounded. But the FPDM module controls the fuel pump duty cycle by applying a pulsing ground signal to the return wire. Sooooo if grounded this would cause the fuel pump to run at 100% duty cycle.

How to rule this in or out? Disconnect the fuel pump driver module (FPDM) and test BOTH fuel pump wires for a short to ground (wire color RD/BK BN/PK). Do not mess with the tank before doing this test.

Also note. I have helped several people with this problem. What sometimes happens is the person drops the tank and can't find anything wrong only to reinstall the tank and have the same problem. It's important to realize the gas tank is being grounded by the mounting straps. So once the tank is even partially dropped this can remove the ground.

It's also possible to use gas tank grounding via the straps to your advantage. If for example the gas tank is supported and then the support straps are un-bolted and then the fuel pressure improves this would "prove" the theory.

Note, edited original post to emphasize this is an electrical problem with a pinched wire and not a blocked fuel line.
 
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It seems to me that your fuel pump is running flat out. What could cause this? A ground short in the fuel pump return line.

How could this happen? Are you interested in an educated WAG? If so, one possibility is that the fuel pump return line was pinched between the fuel tank and the gas hat.

How to rule this in or out? Disconnect the fuel pump driver module and test BOTH fuel pump lines for a short to ground. Do not mess with the tank before doing this test.
01 ford mustang do not have a fuel return it is a returnless system.
 
01 ford mustang do not have a fuel return it is a returnless system.
I'm referring to the the ELECTRICAL lines (wires). Not the fuel lines. This is an electrical problem.

I used the term "line'. Perhaps it would have been more clear to use the word "wire". I have edited the original post to be more clear. As well as added some additional detail. But the real clue is the use of the term "ground short".

It's a great idea to verify the wiring and connector to the FRPS. Look for bent/pushed pins or corrosion. Follow the wiring harness looking for damage (rodent, water, or physical abrasion). Pay special attention to where the engine wiring harness crosses over from the left to right side of the motor. There's a bracket at the rear of the motor that will sometimes abrade the wring harness.

Note, since the FRPS has been changed twice it seems reasonable to conclude that the FRPS is good and the problem is external to the FRPS (wiring should be the prime suspect).

P0193 - Fuel Rail Pressure Sensor Circuit High Input (FRP)
  • FRP signal shorted to VREF or VPWR.
  • FRP signal open (gasoline only)
  • Low fuel pressure (NG only)
  • Damaged FRP sensor.
  • Damaged PCM.
  • High fuel pressure
Also note that having access to an ODB2 scanner that is capable of monitoring operational PID"S might make sort work of this problem. Here's some information on an affordable Windows based unit.

ForScan ODB2 scanner w ELM327 USB
https://www.stangnet.com/mustang-forums/resources/forscan-odb2-scanner-w-elm327-usb.57/
 
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