P0171 & p0174

[Ps4acc88]

Hello everyone,

Well, like title says I got the dreaded codes. Early Sunday morning I went outside to start truck and it cranked for what seemed for ever before coming on. While driving it seemed sluggish and slow to respond.

Took it the local AutoZone where I got a print out of the codes and the system suggested mass air flow sensor. I replaced it and still have same issue. So I plan to return maf .

What truck is doing:

Takes a long time to turn on, sometimes I have to attempt it a second time.

Sluggish, slow to respond to desired throttle

Maf did not fix issue.

Now, I'm no mechanic but I have attempted a few jobs my self so I know a little more than the average Joe. I did some research and a common issue seems to be the pcv valve, I'm not ruling this out but I haven't found anyone who had slow start (hard start) and issue be the pcv valve.

Fuel filter- possibly and i will replace but I'm thinking this might be a long shot. In my case it always seems to be the worst possible scenario.

Which leads me to think the fuel pump is dying out on me :-( ,. Going to check fuel pressure some time this week hopefully.
Wanted to see if anyone has had similar symptoms (including hard start) and what it ended up being. I did do some research on here and saw a video posted on the codes. But little to no information seems to also mention the hard start.


Thanks!

(2007, EB, 4x4, 126k miles)

 

[Bedrck47]

It always helps to know the year of the expy that you are talking about Espexaally when dealing with electrical issues. I know you posted in the 3rd Gen section that's from 2007 to 2017 So should I GUESS that you have a 2010 or 2015 or 2008 Somehow I just hate guessing

If you were to create a signature line it would be very helpful and would prevent me from posting such as I just posted

 

[Big Brian]

have you checked for vacuum leaks?

 

[Ps4acc88]

(2007, EB, 4x4, 126k miles)

Sorry about leaving this out, will create a sig. I did check for vacuum leaks but I could not locate any my self, engine sounds good at idle. May need to have them run smoke through it.

 

[Big Brian]

if you want us to help you it would be good to list everything you have done to it so far...

 

[Bedrck47]

Some information for you

P0171 - System Too Lean (Bank 1)
Description: The adaptive fuel strategy continuously monitors the fuel delivery hardware. The test fails when the adaptive fuel tables reach a rich calibrated limit. Refer to Section 1, Powertrain Control Software Fuel Trim for more information.
Possible Causes: Fuel System:

• Damaged or leaking fuel pulse damper
• Fuel filter plugged or dirty
• Damaged or worn fuel pump
• Leaking fuel pump check valve
• Leaking/contaminated fuel injectors
• Low fuel pressure or running out of fuel
• Evaporative emission (EVAP) canister purge valve is leaking when the canister is clean
• Fuel supply line restricted
• Fuel rail pressure sensor bias

Exhaust System:

• Exhaust leaks in the exhaust manifold gasket or mating gaskets before or near the heated oxygen sensor (HO2S)

EGR System:

• Vacuum hose disconnected on exhaust gas recirculation (EGR) system module (ESM) applications
• EGR valve tube/gasket leak
• EGR vacuum regulator solenoid leak

Intake Air System:

• Air leaks after the mass air flow (MAF) sensor
• Vacuum leaks
• Positive crankcase ventilation (PCV) system is leaking or the valve is stuck open
• Incorrectly seated engine oil dipstick
• Intake air turbulence due to incorrect air filter
• Damaged or contaminated MAF sensor

Secondary Air Injection:

• Damaged secondary air injection system or a mechanically stuck valve

Diagnostic Aids: View freeze frame data to determine the operating conditions when the DTC was set. Observe the LONGFT1 and LONGFT2 PIDs. Refer to Section 2, Adaptive Fuel DTC Diagnostic Techniques for more information.
Application Key On Engine Off Key On Engine Running Continuous Memory
All — — GO to Pinpoint Test H .



P0174 - System Too Lean (Bank 2)
Description: See the description for DTC P0171.
Possible Causes: See the possible causes for DTC P0171.
Diagnostic Aids: See the diagnostic aids for DTC P0171.
Application Key On Engine Off Key On Engine Running Continuous Memory
All — — GO to Pinpoint Test H .


Also read the attached link

http://troubleshootmyvehicle.com/ford/4.6L-5.4L/troubleshooting-p0171-and-p0174-page-1

 

[Bedrck47]

Other information that is helpful

How many miles on the expy?
When was it last tuned up Plugs Coils and or boots, Filters etc replaced.
Has the fuel pump ever been replaced?

Even knowing your elect or mech skills can help

 

[Ps4acc88]

Other information that is helpful

How many miles on the expy?
When was it last tuned up Plugs Coils and or boots, Filters etc replaced.
Has the fuel pump ever been replaced?

Even knowing your elect or mech skills can help

Per the records (just bought truck a couple of months ago)

-Fuel filter has not been changed
-Plugs/coils were inspected at 80k and were in working order
-maf sensor changed by me yesterday
-Checked for vacuum leaks and did not locate any

I plan on checking fuel pressure and if that checks out, take it to a shop to have smoke ran through it to see if it has a leak.

Has 126k miles

 

[Bedrck47]

Plugs are past due being changed
If you do return the MAF sensor get a can of MAF Cleaner and clean the old sensor

QUESTION Do you do your own work??

 

[Ps4acc88]

Plugs are past due being changed
If you do return the MAF sensor get a can of MAF Cleaner and clean the old sensor

QUESTION Do you do your own work??

I tried cleaning the original maf prior to buying new one and it didn't change anything. So I bought a new one thinking the original may not be working.

I do some things my self but I have read the plugs are tricky on these expeditions so I will take it to a shop to have them changed.

 

[Big Brian]

how did you check for vacuum leaks?

agree with Bedrck you are in need of plugs and other maintenance

 

[Bedrck47]

Sometimes its best to troubleshoot a problem rather than just replacing a part Although its sometimes its faster to just replace the part with a new part and then find out nothing changed so its back to troubleshooting LOL

Read the link I posted as there is some very good information available about the Ford 4.6/5.4 engines

Keep the forum posted on your problem and the cure It helps others

 

[Ps4acc88]

Sometimes its best to troubleshoot a problem rather than just replacing a part Although its sometimes its faster to just replace the part with a new part and then find out nothing changed so its back to troubleshooting LOL

Read the link I posted as there is some very good information available about the Ford 4.6/5.4 engines

Keep the forum posted on your problem and the cure It helps others

Will defiantly do, thank you for all your help.

 

[gixer2000]

This should help

 

[Frank Wilson]

It's funny, my wife's windstar and my 4.2 v6 threw the same codes. Both of our engines had the isolator bolt issue. Those wicked smaart engineers at ford used rubber that couldn't handle oil or high temps on their manifold isolator bolts.

Hope you find the issue

 

[JollyRoger]

Read this post: https://www.f150online.com/forums/v...o171-po174-system-bank-what-do-they-mean.html

Sounds like you have an air leak, or maybe O2 sensor(s) are bad? Good luck!

 

[Ps4acc88]

Update:

Ended up taking it to a shop where they ran several test, long story short, the fuel pump is on its way out. Low fuel pressure, now it's taking even longer to turn on. So this leads me to my next question, what fuel pumps do you guys recommend. Oem or is there something better?

 

[Bedrck47]

OEM
I have had good luck with Delphi fuel pumps and you can get one on e-bay just under $200.00

 

[gixer2000]

The certain things that I stick with OEM and fuel pump is one of those

Sent from my LG-G6 using Tapatalk

 

[ExpeditionAndy]

The certain things that I stick with OEM and fuel pump is one of those

Sent from my LG-G6 using Tapatalk

I have to agree with Gixer.

The secret to making a fuel pump last is to never let the fuel get low enough to uncover the pump. The pump is cooled by the fuel so never let the reserve light come on. I try to never let the fuel level get below 1/4. My best friend has his own shop and he has seen fuel pumps go over 200,000 miles and that is the secret. If you constantly run the tank down until the reserve light comes on it will shorten the life of the pump. I have been practicing that with all of my vehicles and so far the fuel pumps are good.