Here's back story, I have a 2000 with a 5.4 and it's been throwing lean codes on both banks (bank 1 is a solid code with freeze frame data and bank 2 is a "pending" code). What it does is, when the weather is fairly cold, it would chug a lot in idle but once you apply throttle it ran fine. It had been doing that for quite some time. I replaced the tps, iat sensor, fuel filter, iac valve, cps, fuel pressure regulator, air filter, several vacuum lines, and ran sea foam in fuel plus in vacuum system. None of this fixed the problem. I settled thinking the exhaust leak at the bank 1 side exhaust manifold was causing it and was waiting to get it fixed. Then, about a week or 2 ago, it started having problems starting but the chugging was gone. It would turn over for about 5-10 seconds before sputtering to a slightly rough idle. But, it always started. Now, tonight, it again started hard and I drove to a friends house but left it running then shut it off at the gas station. When it started, there was a loud pop, some smoke, and a foul smell. I started driving and it ran so-so. But, when I slow down or stop, it will die unless I keep my foot on the throttle. It will restart each time, very hard, but again, I have to keep my foot on the throttle or it just dies. I looked under the hood, nothing looked out of place. None of the plugs are blown out. I pulled codes and got p0171, p0156, p1131, p1151, p0174, p0136, and p1405. Any ideas???

 

Could have a cracked/leaking intake manifold. You definitely have a nasty vacuum leak. When you checked the vacuum hoses, did you inspect the elbows on the back of the throttle body?

 

Im thinking intake manifold as well. Could be gaskets there too.

 

So what was up with the DPFE hose? Was it plugged ? Did it burn off ?

Well first see what's up with that, that DTC usually doesn't lie...- it's tell you EXACTLY where to look.

 

I had a similar problem and change the intake manifold problems gone.

 

I have an 01 5.4 The factory manifolds are junk replace it. That is probably the problem

 

Just checked dpfe hoses and one has a large hole it. Could that be the cause of all these problems?

 

It sure isnt helping anything at all. Replace it soon and let us know what happens.

 

Big hole in the DPFE hose? Probably the issue.

I would make sure your EGR system is all working correctly.

If the EGR is letting in exhaust at idle, it will chug, chug, chug at idle, run lean etc.... and then clear up once you give it some pedal.

It is very easy to do.

http://easyautodiagnostics.com/ford/...e-egr-system-1

 

I wrapped the dpfe hose in electrical tape (local parts store was already closed) and it made no difference. Started hard then revved high and fell to die.