I haven't posted in a while, been busy with family and such. Sunday morning I get in the truck to go to the store and the light is on. I borrowed a scan tool to pull the codes and the two that I got were P0171 & P0174. Does this mean a lean condition? I feel no difference in the way the truck runs or performs. Should I clear the codes and see if they return? Should I buy a scan tool that does more than just read the codes? What would the fix be for these two codes, and could I cause damage by continuing to drive it? This is our only running vehicle. The Dodge pickup in my sig is non-op.
Vehicle: 2002 F150 Screw 5.4L, approx 77,000 mi.
Thanks in advance for any help.
Dave

 

IF let go they can cascade into larger issues.
It would seem that you have a vacuum leak which the biggest contributors to P0171 & P0174 codes....check over the PCV lines carefully....especially the Elbow on the rear of the Throttle body housing.

there are some smaller vacuum lines that go toward the firewall behind the battery check those too.

Is your HVAC able to distribute air inside the cab where it is indicated?

 

The most common on the 5.4's is the rubber pcv elbow behind the throttle body has a hole in it.

As for running it, the code means lean condition detected. It is actually running rich now, which can damage the cats.

Put those codes in the search box for the V8 forum and there is a ton of examples there.

 

Thanks for the quick replies. I don't have much time during the week since it gets dark so quick after I get home from work, but I will check those things. Yes, the HVAC does distribute air into the cab like it's supposed to do. If it's the PCV elbow, I will be relieved. I will check the lines just as soon as I can and I will post what I find. Have patience with me, I'm an old guy.
I just want to fix this problem and I don't want to take it to the dealer cause I'm short of vaseline. (BOHICA).

 

Okay, on Wednesday, a buddy of mine at work asked if he could check out the vacuum hoses. I said sure, so he got up in there (he's shorter than I am) and I mean got up in there and started to check the lines. Right away he said "I think I found the problem!" He pointed to the hose coming off the throttle body going to that green/teal plastic manifold that is next to the power booster. I took a good look at it and around the bend where it connects to the throttle body, it looked like the top layer of rubber was missing. It looked pretty bad.

Yesterday, I went to Autozone and the guy looked at it and said that hose seems to be the culprit. He said another guy with an Expy had the same hose problem. So I left with a new piece of hose.

This morning I removed the old and installed the new. The hardest part was removing the old hose from the plastic manifold. I slit the old one down to the barb and peeled it away from the barb like when you butterfly a shrimp. I DID NOT want to break that plastic manifold! Then I pulled it off the connector on the throttle body. That one came off so easy, I hardly had to pull on it. I looked at the backside of the end of the hose and it was split, almost all the way through, and more corroded rubber. Put the new one on, made sure it was attached as good as I could get it on the plastic manifold without breaking it, and cleared the codes.

Total cost of repair, $3.00.

Now, I'll have to go through a few driving cycles with no more codes to verify the repair fixed the problem that caused the PCM to throw the codes in the first place. I would assume that is the correct mindset to be in, right?

Anyway, I thank you guys for the assistance! much appreciated!

Reloader

__________________
2002 F-150 Lariat Supercrew 5.4L, auto, 2WD
Dark Shadow Gray/Silver, Flowmaster SUV 50 series
18" Kruz Snowdown wheels
285/60/18 Sumitomo HTR Sport HP tires
https://www.f150online.com/galleries/....cfm?gnum=5989

1995 Dodge Dakota extended cab
SLT, 5.2L, auto 4X4 Black

 

Did you clear the codes?? otherwise the old tripped code will still illuminate that CEL. You can disconnect the battery for a few minutes & that will do it.

AND yes it will take a few driving cycles to verify and run on preset table instead of the "corrected" ones it was trying to run on due to the vacuum leak. But not too many, a good 20-50 mile trip should let you know.

Sounds like you found it .....the PCV elbow on the rear of the Throttle body will do the same thing....might want to check it as well , because it is much thinner . Are your brakes a bit more responsive??

 

I did clear the codes right after I fixed it. The brakes....maybe slightly more responsive. I do notice a bit more pep off the line from a stop, but maybe that's just me.

As far as the PCV elbow, for future reference how hard is it to get to and what does it look like? If it's where I think it might be, it looked like it might be a major pain to get to.

__________________
2002 F-150 Lariat Supercrew 5.4L, auto, 2WD
Dark Shadow Gray/Silver, Flowmaster SUV 50 series
18" Kruz Snowdown wheels
285/60/18 Sumitomo HTR Sport HP tires
https://www.f150online.com/galleries/....cfm?gnum=5989

1995 Dodge Dakota extended cab
SLT, 5.2L, auto 4X4 Black

 

Just follow the pipe from the PCV valve around to the back of the engine.

 

here's what the elbow looks like along with the Ford part #....

 

Well, the service engine soon light came back on this morning on the way to work. I was really hoping I fixed it by replacing that other hose. The same codes were thrown as before, P0171 & P0174. I guess I can be thankful that they're the same codes and not different ones.

88racing, thank you for the pic. That is very helpful! How difficult is it to get to, and how is it attached at both ends? It seems like it would be a fairly simple repair, just remove & replace. It's getting to it to R&R that I'm wondering about. Others have said that elbow getting a hole is a very common problem. I hope that will be the problem on my truck. I haven't worked on vehicles for a long time and that is why I am asking so many questions. I'm an older guy so it's not like I am always under the hood or under the truck all the time, but I want to fix it & fix it right.

 

From what I see it would be easier if you have hands the size of an 8 year old. I am not looking forward to replacing mine when the time comes. I think I will end up pulling the throttle body and cleaning it when mine goes to give me easier access.

 

I usually use a flat screw driver and pry/push it off the back and then get the plastic hose out with it still on and pull the old one off and put the new one back on....then get it back there and get my hands in there and push it on....using a little lube inside the elbow will help to get it pushed on....

 

I got the old one off and it looks a lot bigger than the new one. At the dealer, I showed the guy the part number and he said the last two letters of the part number were upgraded to CA from BB. It looks like the new one will fit inside of the old one. Is the new one the correct elbow for a 2002 5.4 2v engine?
I'm stuck here.....Can someone chime in? I really could use some advice.
I posted 5 pics in my gallery of the two. I did not open the bag with the new boot just in case by my luck it's the wrong one because if the bag is open, i cannot return it.
The I.D. of the new one appears to be 5/8" & the old one is 3/4". Is the elbow supposed to stretch out to 3/4"? That seems like a lot.
The other thing is, I couldn't see any holes in the stupid boot.

 

Sounds like they might have given you the one that goes on the PCV and not the throttle body end. Take a look at the pic a couple of posts back.

You must have gone to villa Ford. I went there once and had to show the parts guy where the PCV was located on my V 6. He couldn't even find it on his diagram on the computer, plus he was rude.

 

Yes, I did in fact go to Villa Ford. It's a good thing I didn't open the bag, and by the pic that 88racing posted, I can see the difference. I just had to study the pic a bit more. Could it still be leaking even if I don't see an actual "hole"?

__________________
2002 F-150 Lariat Supercrew 5.4L, auto, 2WD
Dark Shadow Gray/Silver, Flowmaster SUV 50 series
18" Kruz Snowdown wheels
285/60/18 Sumitomo HTR Sport HP tires
https://www.f150online.com/galleries/....cfm?gnum=5989

1995 Dodge Dakota extended cab
SLT, 5.2L, auto 4X4 Black