Hey Guys,
I will be working on my Step-Sons 2002 Ranger starting tomorrow. He has the P0171/P0174 codes and it is ideling and running a little rough. I can finally get working on this truck, and I have to get it done because he is do for inspection at the end of the month.
Keep in mind I did do a search for this problem for the V6 but I couldn't find any info on the V6 but as we all know, there is a ton of info on the V8's.
Last month I put new MC Plats in it, new wires, new air-filter, and a new Fuel-filter and cleaned the MAF.
I will be checking/cleaning his IAC, doing the vacuum/suck test on the EGR valve, and checking out his PCV Assembly and looking for any vacuum leaks. Anyone have any knowledge of known problem area's on these V6 engines that you can direct me to.
I havn't had to work on a Ranger in a long time (6+ yrs).
I ran into these same codes on my 5.4L V8 - 03/2008 and finally got it worked out my replacing the PCV Assembly (purchased from Ford) and cleaning the MAF sensor really well w/ CRC Elec. cleaner.
Any and all help is greatly appreciated.

Thanks,
TJK

 

Which V6?

 

Hey glc,
I got thinking about that yesterday when I was working outside and realized I forgot to put in my original post, the engine size and mileage. It's the 4.0L and has 118,000 miles. My bad, I should know better....:o
Anyways, my stepson stopped in late yesterday and said the truck was ideling and running real crappy (and it was from what I could hear) so I popped the hood and I could hear a serious air suction/vauum noise. I followed the noise to a 90 degree, 5/8" ID, rubber elbow on the "front" of the engine and it had a pretty big tear/hole in it. I don't have a Haynes manual for this vehicle so I can't give you the part name. The elbow goes to a hard plastic line that leads to the rear of the engine. There is a small 3/8" hose that sits on top of that elbow coming from the same area at the front of the engine and this line runs to the rear of the engine as well. I had to lift the top Rad. hose to access these lines. Both lines run from metal hard line tube connections in the front and then run along the side of the top plastic intake to somwhere in the rear of the engine. Anyway, I repaired it with a 5/8" ID hose using a rubber hose unicoil to make the 90 degree bend so it wouldn't kink. Immediatly the idle came back and the engine was running smooth again. I cleared the CEL with my Equus Scantool and we will have to wait and see if the 3 codes stay off. Forgot to mention, when I 1st checked his codes yesterday, he had the code for random misfire as well but I have seen that before with these 2 other codes when a large vacuum leak is present.
I will keep eveyone posted as time goes on and hoping this was his only problem for the dreaded P0171/P0174 codes. It took alot of time,checking,and a few minor repairs to finally find mine on my 5.4L V8.

For my on knowledge, what are the lines that I found called and what is there function. I'm trying to save my step-son some $$$ and not have to buy a manual. So far it hasn't cost him anything because I had the parts on hand. Your answers on these questions is greatly appreciated.

 

A manual is only 20 bucks and it would be money well spent if he's planning on keeping the truck.

 

Ye I know manuals are cheap, I have plenty of them in my shop for the family vehicles I work on or have worked on in the past. That's the issue, he's talking about trading for a full size truck. I was hoping to get away with a few answers from ppl on here for anything that they have ran into in the past on this engine.
The hoses I described in my above post, you have a description of what they are.

 

P0171/P0174 + 4.0L v6 = Bad intake mani gaskets and/or injector o-rings.

That's the common cause of those codes on 4.0L v6 Rangers.

 

Here was the problem and the fix.
I found the problem in 5 minutes and fixed it in 10 minutes. On the front of the engine block, right in front/under the "plastic" intake, there are 2 lines that come out and run to the rear of the block. These hoses sit under/behind the top radiator hose. Both lines are holding vacuum. The top hose was fine. The hose underneath comes off the engine block with a 5/8" ID rubber 90 degree elbow. There was a pretty good size tear in that elbow. I had some 5/8" hose kicking around and used a "unicoil" to make the bend so it wouldn't kink the rubber hose. The hose goes from the front of the block, turns 90 degree's and then goes into a plastic hardline to the rear of the engine.
Problem fixed. Cleared the codes, he drove it for 100+ miles and the code stayed off and all of his readiness monitors cleared to green (PCM status ready). It passed inspection yesterday. That was the quickest I have ever seen 5 monitors re-set after a CEL clear/ PCM re-boot.
Sharing this info, just in case someone has a 4.0L with this problem. It was an easy repair because, when I lifted the hood, I could hear the massive vacuum leak.
In the past, I have found problems and made the repairs and forgot to post what I did.

Oh Ye. it's fixed and running great.......

TJKinCNY

 

Thanks for the answers Alfred.
For my own knowledge, why would the injector o-rings produce those codes.
I am sure you know, those codes stand for B1 + B2 running lean.
The other solution you offered I knew about and was really hoping that wasn't the problem. That gasket replacement looked like a pain in the keester.
As you read earlier, I don't have a manual for that truck, can you tell what those 2 lines are that come off the front of the engine, especially the one hose I repaired.
Thanks for your input.
TJK