2000 F150 5.4L $x4 4R70 Manual Transfer Case... (should be enough info )
Ok so I got my wonderful POS running good for a little while now, then the other day....

I parked it the night before. I got up early when it was cooler (5-8degrees celcius) not tropical but not damn cold by any means, fired it up and suddenly a nice idle surge started happening. But once it is taken for a drive or warms up is gone. I had the issue before but somehow through the process of elimination it was "cured".

Here is the LIST of what has been changed/repaired/cleaned ect.
PCV assembly (hose elbow and valve)
Cleaned throttle body and egr ports
MAF was replaced and cleaned
No obvious vacuum leaks (18 or 19hg at idle, bad memory)
Suck tested EGR (good, functions)
New throttle body gasket when i pulled it off to clean, just cause I thought it should be done.

There may have been more but can not recall at the moment...one thing i noticed is when it surge's and you pop the air filter off and cover the MAF port on the sensor it levels out. Doesn't seam to surge any more... weird since once its warm the problem disappears... Along with the surging there are three codes that show up, P0171 P0174 P0156.

Appreciate the read over and would like to get some further insite into the problem... Big Thanks in advance.

 

The 171, 174 codes are bank 1 lean, bank 2 lean respectively. The 156 says bank 2 02 malfunctioning. The lean codes point to the Maf {which you've already found}, or to a vacuum leak.
I would clean the Maf, by spraying it with any non residual cleaner.
The O2,{rear sensor, drivers side} I'm not sure if it is caused by the lean codes, or if it is a separate issue. I would clean the maf first, Just try spraying to break up any crud. The little wire is very easy to break, I don't recommend touching it.

Just check the wiring to the O2, clean the MAF, and see how it runs.

Edit:Either have the codes cleared or disconnect the battery for 1/2 hour. I prefer to have them cleared if it's the service is available.
In most States Auto zone will do it for you.

 

Codes have been cleared, I don't use a garage for anything. And around here no one scan's for free it 80-130 bucks per scan no matter they find anything or not. Have my own personal code puller. But the codes come back within no time at all.

I will be looking at the 02 today, with the way the codes appear that may just be the issue and potential cause. My V6 had a similar problem the drivers bank front sensor went and caused an inconsistent idle problem. Replaced and gone.

As for the maf it is/was cleaned and in the repaired list Thanks. Any other idea's before I get down and ugly with it lol

 

Iac?

 

everytime i start my truck in cold weather(about the same temp as you mentioned) the rpm goes up and down a little bit until it idles down. what brand pcv valve did you use? since you replaced the pcv assembly, i'm assuming that you had the p0171 and 174 before? maybe they didnt get cleared?

 

all FoMoCo parts used. I have a code reader lol sorry not being rude, just somethings are being overlooked in what I posted. IAC was cleaned(forgot to put on the list), wasn't dirty really and the voltage is seamingly correct according to the ol haynes bible... I am beginning to lean towards EGR/DPFE as a compounding problem since it doesn't occur once heated up to operating temp.

 

ok so does that code reader have the ability to erase the codes? or are you disconnecting the battery? the dpfe would have nothing to do with it. and the computer would throw a code for the egr. and the maf was replaced? did you get a new one or reman?
http://www.v8sho.com/SHO/TSB0197HO2SServiceTips.htm
this should help with the p0171/174 codes.
any emissions problem will pretty much cause a cel for that particular problem.

 

yes i reset the codes multiple times same codes repeatedly. I erase, drive across town and then turn truck off, start up drive back to house, park. restart scan and bang theres the codes. (again neglected to state that previously, brain must have been on vacation before)
It was out of another running fully functioning vehicle. Same motor, same year (nearly three months difference lol to be accurate).
The part that worries me is it does not get the code from the chugging it only shows after being driven. I can start it up, warm it right up and turn it off, go to restart and run fine, scan and no code. Come back two hours later repeat and same scenario still with no codes.
Rather bothersome.

Thanks for the link.

 

p0156- Disconnected sensor
· Pinched, shorted, corroded wiring or pins
· Crossed sensor wires
· Exhaust leaks
· Contaminated or damaged sensor
· Chafed/damaged wiring

p0171/174- Contaminated fuel injectors
· Low fuel pressure or running out of fuel (fuel pump, filter, fuel supply line restrictions)
· Vapor recovery system
· MAF contamination
· Vacuum leaks
· PCV system concern
· Leaking gasket
· Stuck EGR valve
· Leaking diaphragm or EVR
· Exhaust leaks before or near the HO2S
· Secondary air concern
· PCM concern

 

Thanks Matt, I'll be looking at the 02 sensor today and as for the rest I won't be able to purchase parts until next week. But definitely appreciate the help deciphering the issues. Will update with the particulars once I come across them

 

That's all IAC Jay. When you clean those, you have to do so correctly. A few points in cleaning that sensor.

First. - Ford deems that sensor uncleanable/serviceable. Keep that in mind.

You have to use compressed air o forget it.

You have to use the right and wrong chemical cleaners in order to be successful, - there's a sort of~trick to it.

You must work the mechanicals (inside the sensor) on the bench w/proper cleaner/lubricant made just for this type of application.

It's all easier than it sounds, but yea, that one has to be done right. How did you clean it?

That was the last sensor I replaced from the original one. I had over 200,000miles on the original and probably cleaned it 10 or 15 times. The original wasn't bad when I replaced it.

Not sure why or what you were doing pulling the air box off and fingering the MAF port, but -to each his own I guess

Lean codes are a leak, both banks point up (something up top) , where if one banks been leaning in in the past and now both are -usually points to the intake gaskets.

Have you had 401's or any 400 series codes recently ? Those can get thrown as well, if the leak is in the exhaust = EGR pipe/O2 bung, - Those leaks generate codes as well.

The 02 code is simple, I've had that one many times before I finally learned how to splice stainless and aluminum O2 wires lol. Best advice there is, - don't ever do it lol. - Yea just purchase the right ones with the correct lines and be done with it. BUT! With Rosin Core, you can splice them up nice, but it's a necessity to use Rosin Core Solder (the good stuff) and you absolutely need Rosin Flux to assist or it won't work.

All these codes can come from work done in the past as well. I can't be specific unless I write a frickin novel, but you know what has been done so far and if you came here or followed a instructional every-time, you should be alright, but it doesn't hurt to go over your work. Lines get old and break down. I've replaced the entire vac harness twice. Same w/PCV system. They go bad/dry up and turn to crap.

Good Luck

 

if you touched the MAF with your finger chances are you messed it up

 

lol Thanks guys. Was thinking of replacing all the VAC lines but ford wants an obscene amount for the OEM ones, was wondering if a guy could go all rubber like on the old CARB trucks? I was under the truck yesterday and noticed a couple small leaks in the exhaust, passenger side manifold to down-pipe as well as at the cross over under the trans.
I didn't physically "touch" the wires of the sensor just blocked the flow to the inlet of it. But you know you gotta give the truck some lovin' time to time
Yeah, i understand the method of it and did use a MAF sensor safe cleaner on it. It was in a cleaning thread with the TB I believe on the fordf150.net tutorial. I admit it was tricky but simple, but also could have been a wasted effort as it was a short term effect .

I will add a new IAC and probably intake gaskets to the parts list to order on monday. As well as that one 02 sensor I am pretty sure it just bit the dirt with 240k km on it. Thanks again, I'll be happy when this one runs right.

 

240k on an O2 sensor? What about the other side? Bosch, who makes them for Ford, recommends changing at 100k or 160,000km. I suspect that if it has 240k on it it needs to be replaced too. FWI I swap mine every 50k (80,000km).

.