a few days ago i posted about my 2006 f250 5.4 running lean p0174. i borrowed a better obd2 scanner and this is what it said

p0171 and p0174

po174
FF data ($7E8)
fuel sys 1 cl
fuel sys 2 na
calc load % 100.0
ect *c 82
stft b1 % 14.1
ltft b1 % 19.5
stft b2 % 3.9
ltft b2 % 20.3
eng rpm 3593
veh speed km/h 45
spark adv (*) 7.5
iat (*C) 2
maf (g/s) 159.96
tps (%) 76.1
o2s b1 s1(v) 0.750
stft b1 s1 (%) 10.9
o2s b1 s2 (v) 0.815
stft b1 s2 (%) 99.2
o2s b2 s1 (v) 0.870
stft b2 s1 (%) 10.9
o2s b2 s2 (v) 0.825
stft b2 s2 (%) 99.2
fp/vac (kpa) 259.8
command evap (%) 0.0
fuel level (%) 84.3
evap_vp (pa) -8.5
baro (kpa)97
cat te 11 (*c) 669
cat te 21 (*c) 669
ecu volts 14.576
load value (%) 90.2
eq ratio 0.999
rel tps (%) 64.3
ambient (*c) -7
tps b (%) 89.4
acc pedal d (%) 74.9
acc pedal e (%) 71.4
acc pedal f (%) 61.2
command tac (%) 99.6

i know this is a lot of info but i would appreciate it if some one could help me figure out why my truck is running lean. i dont know much about engines and i would sure appreciate some help. THANKS.

 

I have a 2006 Ford F250 5.4L SC

On the OBD2 machine it should give you more codes with this one p0171 code. Make sure when you look at the OBD2 machine on the top right hand corner it will tell you if you have more then one code. Then click on the blue button. Then scroll down it will give you more information on all the codes.

The one you have is p0171 which i believe is TOO Lean Bank 1

You will need to replace your plug or coil on a cylinder. It might be the number 4 cylinder which is a little tight to get too. You can change the plug first but sometimes it easier to change both so you don't have to this again. The spark plug is about $11.00 to $13.00 dollar (Motorcraft) and the coil will cost between $40 - $60.00 where every you go.

Again best thing to do is go back and check the OBD2 machine and make sure you have more then this one code. I believe you do and it will tell you the exact cylinder.

If it's the number 4 cylinder let me know and I can tell you and easy way to get to that one.

I hope this helps.

 

Sorry I believe getting to the number 4 cylinder might be easy to get to. My expedition number 4 was a little harder.


Again double check the codes. It could be anyone of the cylinders but you want to replace the correct one. If it's not any of the cylinders it might be a dirty fuel injector.


good luck

 

Po171 and Po174 are lean codes on the left and right banks....mine did that on my V-10 and it was a crack on the pipe on the drivers side valve cover to the air cleaner tube. Those codes should not be a plug or coil.

 

it is showing 4 codes p0171 and the p0174 codes and it also shows p0171 pending and p0174 pending

 

Let us know what other codes you got. Maybe someone had those codes.

When I had my code p0170 I also had some other (300 codes) which was misfire on cyl #5 and #6. This was a bad coil and a bad spark plug on my 2006 Ford F250 5.4L

 

Vacuum leak. LFTRIMS on both banks around 20% tells you that.

 

Vloney - Where should (06 CC 250) start looking for vacuum leak?

 

just changed the fuel filter a couple of hours ago and it seems to run better now. i dont have a cel light right now cause i cleared it. i have tried to make it come back on but have been unsuccessful. on real cold mornings if i nail the gas from a stand still the cel light come on and thats when it gives me the p0171 and p0174 codes. maybe the dirty filter was restricting fuel flow or something, i dont know. the gas that came out of the old filter when i took it off was extremely dirty almost black. hopefully the dirty filter was my problem. i will try the next chance i get to see if i can get the light to come back on and check the codes again.

 

That's Great!!! totally forgot about the gas filter.

When I got my codes I had some plugs and coil problem. I hope there was no confusion. If you do get more codes let us know.

Keep us all up to date.


Good Luck - 06 CC 250

 

I don't know how similar the 2006 vacuum system is compared to a '98 5.4L. Do you have a hard plastic vacuum line assembly with a PCV valve and a couple connections to the intake manifold? The connection ports are soft, and the main distribution line is hard plastic. On the '98 version, there are several rubber elbows that wear thin over time, and they develop cracks and holes, thus producing the familiar PO171 and PO174 failure codes. The main port at the rear of the intake manifold is almost impossible to see...you have to reach back and feel it. Anyway, if you have this setup, I would remove it and check the elbows. Mine gets replaced about every 4 years. If you check some of the other threads, they mention that this assembly has two versions: one with a straight connection for that rear intake port, and one with a 90 degree bend. The one with the straight port has a recess in the body that perfectly fits a worm gear clamp (hose clamp). I just found out last night that the worm gear clamp is needed on my version of the '98 5.4L. Without the clamp, the fitting leaks, due to the tight fit against the sheet metal. I heard that newer engine compartments have more room at the back of the engine. This assembly can be purchased at the Ford dealer for about $50, and it comes with a new PCV valve. Good luck, and best regards. Some of the other discussion threads cover these failure codes in greater detail. Check all your other vacuum lines, too.

I couldn't add the images because the message became too long with the photo embedded into the message. If I figure out how to upload the photos, I'll add them.

 

my pcv system is different, it doesnt have rubber elbows. its got plastic connectors that go on the valve cover and the intake. it doesnt even have a visible pcv valve i think its built into the valve cover. i reset the computer and now the only code it shows is the p0174 and p0300. it is now backfiring through the intake at full throttle now.