Sorry I'm new to this thing could gave sworn I put all info somewere though. 04 F150 SCAB XLT 4x4 5.4L 3v 127,000. Regular 5k oil change 5w-20 synthetic, air filter, clean MAF, and clean TB. Do to this problem just replaced TB, fuel filter, TPS, MAF. (was told cleaning the o2 sensors may help, and at this point I'll try anything it's gulping $30/day in fuel)

 

This might be one of those things were you have to visit your dealership or mechanic. If you have covered all of the basics then it may require some advanced tools to diagnose. Since you are getting both codes I would be leaning towards the vacuum leak or something of that nature. If you were just getting one code for one bank then you could look at injectors or things that pertain to that bank. I am assuming you have reset the codes since you have done all of the cleaning and replacing. The other thing that comes to mind is that you mentioned you replaced the TB, maybe the o-ring between the plenum and the TB is pinched? Just a thought. I have had trouble with these codes in the past and they are a biatch to diagnose.
Look at pages 31 & 32 on this pdf.
http://store.roushperformance.com/im...als/401633.pdf
It shows the vacuum locations on the plenum that could have come loose.

Here is some info on p0171 (& p0174) The EGR system on these trucks is incorporated with the VCT system but the rest is valid


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
�� EVAP canister purge valve is leaking when the canister is clean
�� Fuel supply line restricted
�� Fuel rail pressure sensor bias
Air Induction System:
�� Air leaks after the mass air flow (MAF) sensor
�� Vacuum leaks
�� PCV system is leaking or the valve is stuck open
�� Improperly seated engine oil dipstick
Exhaust System:
�� Exhaust leaks in the exhaust manifold gasket or mating gaskets before or near the
HO2S
EGR System:
�� Vacuum hose disconnected on exhaust gas recirculation (EGR) system module
(ESM) applications
�� EGR valve tube/gasket leak
�� EVR solenoid vacuum leak
Secondary Air Injection:
�� Damaged secondary air injection system or a mechanically stuck valve

Air Measurement System:
�� Damaged or contaminated MAF sensor

 

Thanks for all that I'm thinkin a vacuum leak as well I'm going to mess around some more this weekend if still ain't got no luck I'm goin to give up and go by ford dealership on Monday. I added some sea foam to the fuel never heard of it before what do ya think about it?

 

I am not a big fan of seafoam. Too much solvent and stuff that's no good for o2 sensors and cats. I would recommend techron fuel system cleaner or gumout with regane. Oreillys auto parts store has buy one get one free right now if you have this by you. Wish I could offer more.

 

So..... Found the vac leak. Vacuum line that goes into the back of the intake came off I've gotta try and get it back on but not sure how. I can't reach it.

 

The lord is great and worthy to be praised!!!!! Prayed long and hard about was led to a local shop that run a diagnostic on and located the leak for me $50. It was where it connects to the back of the intake, I removed the fuel rail leaving the injectors in ( passenger side) and got was able to get to it easy as could be! Got it and everything plugged back in, started her could instantly tell a difference let her idle for about 15 min stayed at about 750 rpm the whole time. Couldn't have done that yesterday would have stalled after 2-3 min! I thank the lord most of all for the patience and all y'all on here for the help! Saved between $200-300. Not much but a lot to a Marine with a family! Thank y'all!!

 

Glad you got it figured out. Glad you also posted what the problem was also. Seems to happen to often that people don't post what the end result or solution was. Hopefully this will help others in the future. Keep on truckin!

 

4 3v
The 3 valves do have the retarded elbow, you think Ford was goin to put it somewhere easy 😂😂😂