My 2000 5.4 has the P0171 and P0174 and from what I read it normally is the MAF sensor. Well, after a year or so, I finally got around to putting a new MAF in a few days ago. I cleared the codes and they came back within a few mins. of the engine running. Cleared them a few more times and they come back.

Runs pretty much fine. Once in a while when I start it, it runs a little rough.

What's my next step? Looks like checking the hose to the PCV, and then what?

 

Check the PCV hose elbows. They get soft and crack and cause a vacuum leak which throws a lean code.

 

The pcv hose elbow is where I found mine. Hopefully my codes don't come back and make sure you check the backside of the hoses cuz mine wasn't in plain sight.

 

Thanks for the info. I haven't had a chance to check mine yet. I hope that is the problem.

 

I have a 99 E350 with the 5.4. It has the same code PO171, mine also has a severe spark knock under load. Plugs and boots were replaced about 4000 miles ago. Is this normal with a leak in the pcv hose?

 

Sounds like you may have a fuel problem. Usually the pinging isn't a side effect of the code. I would check the hose, cleaning the MAF and checking the fuel pressure as well.

 

'00 E250 with the 5.4 gasser, 255K miles.............

Had misfire codes along with lean bank one and two popping up in what became a predictible pattern---once the weather turned "cold" even overnight on a normally hot summer day. Finally tracked the problem down to a vacuum leak but not at the PCV hose although I did check that entire hose carefull.

Here's a link to my thread and result---it might be helpful: https://www.ford-trucks.com/forums/1...-misfires.html

 

Well, it's been a few months. I decided that until I had to get into the engine, I'd wait. Well today was the day. The hose off the PCV valve had a large tear in it in just before the first elbow off of the PCV valve! Hopefully that was it. I went to Autozone and of course, they didn't have quite the right elbow although it was marked Ford.

The end that was to go on the PCV valve and the new hose was too large. I cut off the old hose and fit it over the PCV valve connector first, and then put this new hose over it. It was quite tight so it should hold. The other end of the new hose was the correct size.

Don't know if it worked. I will later though as I'm driving across town.

As for what the other Handyman said, Pinging can be a loose spark plug that is going to blow out. That concerns me with Handyman's problem because he just had the plugs replaced. If it's still doing it, check those plugs. You do not want one to blow. I got lucky with mine. It left enough threads to not have to repair it. Damn lucky! It did tear the boot and break the plastic mount of the COP. I got a new boot and now the COP just sits on the top of the boot and is not mounted, but it's been that way for over 20k miles with no problems.

So LXman and others from other threads were right I think, as the PCV hose was cracked exactly as you said. And it was soft just as you said.

I went into that area because my daughter screwed up the shifting and now it won't start in PARK. I wanted to make sure it isn't the tranny or the connection there and it isn't. New thread!

 

Now I am getting p1132 and p1152.

 

And after a few times of clearing them, I'm clear of codes!

 

Glad you got it straightened out!!

 

check egr pipe at driverside front tire look for a leaking cap bolt or he in the pipe it's self you can hear it if it's realy bad if you
Have someone start it while listening by the drivers side front tire .i fixed mine with some air-conditioning aluminum tape worked perfect but you gott reLy clean it good