Because you asked if you have a DPFE in post #2.

 

seems like it me of my prior f159s had a hole in hole that threw code(s)

 

DPFE would throw a P0401 code.

 

Went to two parts houses “we just sell parts we are not mechanics”. Advance located pressure regulator behind the engine in 4.2 so I would have to crawl under truck with it running to disconnect hose. YouTube videos showed regulator in different spots and on different sides.

 

If you can find the other end of the hose it may be easier to pull it there.

 

So if I unplug and the psi goes up then what?

if I unplug and psi doesn’t go up then what?

 

If it goes up the FPR is good, if it doesn't it's bad. If fuel drips out of the hose it's bad.

 

Finally today I tackled the project. Went to change pcv and discovered the infamous hose on very back was collapsed and when removed I could see holes and cracks.
Codes appear gone
also replaced battery

 

Done hopefully

 

Still no check engine light
when I topped off today I’m averaging less than 11 MPG

 

Not even getting a response

since I fixed the check Engine light po171 and po174 by replacing the hose is there anything I should do since my truck has been running in a lean condition for at least a year based on the codes??
my air filter from last August has about 7-8 thousand miles.
appears I’m getting under 11 mpg.

 

Disconnect the battery to clear the memory and let it relearn. What are you using for gas? My last tank was some offbrand stuff that I suspect had more than 10% ethanol and I got 12 mpg on it. I normally get around 15 in town and 20 on the highway. Are your tires stock size?

 

Today check engine returned for po455 the oil and water light came on and the temp gauge dropped to nothing even the 4 low light illuminated but engine died . It would start and immediately die. Then nothing. All I had with me was fuel pressure tester and code reader . Finally it started and I drove it home . Po460 code when I arrived home.
fuel pressure with engine off was 15-20 psi
2000 f150 4.2 4wd

 

https://www.obd-codes.com/p0460
https://www.obd-codes.com/p0455

What is the fuel pressure with it running?

 

I don’t know bc at the time it wouldn’t start
a d engine was hot difficult to put gauge on