Popping up with P1000, P0171 and P0174 on my 99 4.6 F-150. Familiar with 71 and 74 but not sure about all three together. Sometimes it gets down the block after clearing with the scantool and pops back up, other times I can go a couple of hundred miles before it pops back up and have been changing vacuum lines trying to remedy

 

Since many of us do NOT have a DTC cross reference handy and you must know what each aludes to, please list the main causes of each DTC you show.

 

Obviously you have internet access so wala instant DTC cross reference

http://www.canobd2.com/DtcLibrary/Default.aspx?Make=

Add the site to your favorites list for easy access.

P1000 Ford OBD Systems Readiness Test Not Complete
P0171 Ford Fuel System Too Lean (Cylinder Bank 1)
P0174 Ford Fuel System Too Lean (Cylinder Bank 2)
Vacuum leak affecting both sides, pcv line - vmv line - intake gaskets.......

 

No need to go anywhere but FTE for the DTC codes.

https://www.ford-trucks.com/article/idx/7/0/

 

Sometimes the P1000 comes up if the PCM hasn't cycled though a heat cycle.
It means the temps are too low and not ready for closed loop I believe.

The other two are lean conditions caused by either a dirty MAF or PCV hose failure.

 

As long as you're working on a Ford.....anything else you need options

 

The 171/174 are both banks oxygen sensors responding to usually an air leak in the intake tract.
The 1000 code will be triggered everytime you clear a code/s which is a normal happening.
It takes several drive cycles or more to clear a 1000 code because there are many tests the PCM program has to make under varying conditions and they must all pass.
Many people with common 'readers' never see the 1000 code and it does not light a CEL lamp because it in it'self is not a trouble code but indicates some test catagory did not pass.
A 'scanner' if used by a knowlegbale person and it has enough capability, can go in and request what test functions failed.
But you always correct the indicated failure P coded first, then do enough drive cycleing to see if the 1000 code clears. Sometimes it takes a few weeks.
Remember, everytime you do a clear, you set the 1000 code automatically and start all over again on drive cycling. The pits but that's the way it works.
Usually a 1000 code won't fail inspection unless they find the cause is one affecting emmissions for which there usually will be an associated codeing. For instance a gas tank system incomplete test may still pass in some states and sometimes takes weeks to reset. This one by it'self can cause a 1000 code without a trouble code.
Hope this gives you better insight into an operating system more complex than you may have thought.
Good luck.

 

Thanks to both Ron W. and KingranchMan02 for the code links.

I do have a top line reader and a list of the codes printed out but not by my computer, and I sure have not memorized them, so I think if someone lists a code, it might be helplful for many readers to also give a short description of the error.

Thanks again.