2001 Ranger Edge 3.0 (P0171, P0174, P0113) help needed!

[Keene1981]

(note: Also posted this in the 3.0 V6 forum but I'm at a loss and need the truck to job hunt soon so it's kinda' urgent... sorry in advance if posting it here is bad)

Long time lurker and I've found advice here that has helped me in the past, but I'm completely out of ideas and need some help. Forewarning, this will be a little long as I want to say exactly what I've done so far and the results. I've posted a few other places but so far I've just been pushed back to re-checking what I've already checked. Please, please help if you can as I need a vehicle running so I can go for job interviews after being laid off due to outsourcing!

OK, I have a 2001 Ford Ranger Edge 4x4 with a 3.0L NA engine that has thrown the infamous P0171 and P0174 combination codes, but also recently showed a confirmed the P0113 code (Intake Air Temperature Circuit High Input).

This all started a few months back when the truck would lurch at highway speeds between gears and I'll also note that I have an exhaust leak in the muffler I think as I've been seeing exhaust come up between the bed and cab since winter (whether this is irrelevant or not, I'm not sure). Eventually the truck started coughing and sputtering when pulling out of idle... this building to a crescendo one evening when the wife was out and it died on her completely when pulling out from a stop light in the middle of town. Then it started happening at highway speeds, actually dying out on me on the interstate. I was able to idle/gently tap the gas with my flashers on until I hit an offramp, coasted to a gas station, and got her towed home.

It idles rough at initial start up from cold, and I can get her a few miles up the road before she sputters and dies out on me again. It seems that once the truck is up to operating temperature and the pedal is pushed down after pulling out (or if trying to go slightly uphill), the truck begins sputtering and coughing with absolutely no power and the RPMs won't go over 1,500 or 2,000-ish most times. If you let off the gas to idle again, the truck will seem to regain consciousness for a moment then once you push at the gas again it does the same thing. It usually does this a few times, RPM max getting less and less, before absolutely dying where she stands.

I've run a diagnostic tool on it and will post the results below. Not sure beyond the trim levels as to what would be considered relevant information, so I'll just put everything I wrote down. I took notes of the finding at both idle and at 2,500 RPMs. I'll post those findings below.

CODES: P0171, P0174, P0113

Short Term Fuel Trim (Bank 1): (Idle) -3.9 to 0.0 ........ (2500 RPM)-9.6 to -2.3
Short Term Fuel Trim (Bank 2): (About Same for Both as Above)
Long Term Fuel Trim (Bank 1): (Idle) 7.8 to 8.6 ........ (2500 RPM)5.5
Long Term Fuel Trim (Bank 2): (Idle) 9.4 .......... (2500 RPM)7.0 to 10.2
Fuel Trim Bank Sensor: (Idle) -2.3 to 0.8 ......... (2500 RPM) -5.5 to -3.1
MAF (LB/M): (Idle) 0.64 .......... (2500 RPM) 1.80
ABSLT (TPS): (Idle) 16.1 .......... (2500 RPM) 21.6
Fuel System 1 Closed Loop Status: Closed
Fuel System 2 Closed Loop Status: N/A
02 Voltage Bank Sensor: 0.200
Fuel Pressure (Key ON): 43
Fuel Pressure (Idle): 67


So far, I have:
* Cleaned the throttle body out
* Cleaned the MAF/IAT combo twice
* Checked for the obvious vacuum leaks (hoses to sensors and main hose from MAF to TB, brake booster hose, PCV hose, etc., all seem good)
* Cleaned Idle Air Control Valve
* New fuel filter
* New fuel filler hose (old one was rusted out bad and leaking)
* New PCV valve and elbow
* New EGR Valve
* New Throttle Position Sensor
* Multimeter check on MAF/IAT combo, all looks smooth and good there
* Fuel Pressure tested on rail

Given the codes and the resulting findings from running the fuel trims, what (in your opinions) are the most likely culprit?

Failing fuel pump? Sticky injectors? A vacuum leak I'm not seeing yet? I'm at a loss, the only garage in range I can get it to without it dying on me again is a joke of pure highway robbery, and I just got laid off after being outsourced. I need to fix my truck to get another reliable job and currently at a loss for funds to just throw parts at it.

What would you all check first and how? Any tips on how to narrow down the culprit so I can get Ol' Red back at it and me working again?

I've completely run out of options to check and just hoping there's something I'm missing. Thanks in advance, y'all. I would greatly appreciate any feedback on what you think the problem is!

 

[Spott]

If your exhaust leak is upstream from any of the O2 sensors, then you should start by fixing that. At certain engine speeds, the leak can actually draw fresh air into the exhaust system, where it's seen by the O2 sensor as having too little fuel in the mix, so the computer mistakenly adds more fuel to compensate for the perceived error. Since the leak is still sucking fresh air, the computer thinks that first fuel adjustment wasn't enough, and adds even more fuel, on and on until it reaches the operating limits and reports an error. Having the fuel/air mix off that far will make the engine run poorly.

 

[Keene1981]

Exhaust leak -- at least as best as I can see -- is from a split right along the seam on the bottom side of the muffler. I suppose that's downstream from the O2 sensors as they're up pre-cats I think. Could that still suck in oxygen and throw the codes, or does the exhaust leak have to be before the O2 sensors to throw codes?

 

[Spott]

No, if it's downstream from the sensors it won't affect them at all. It should be fixed at some point, but it's not the cause of your current problem.

 

[Keene1981]

Gotcha'. At least that is ruled out as the current culprit, then.

I'm not to wise on reading the fuel trims and all the technical stuff yet (I'm a bolt 'er on and seal it kind of guy and the numbers baffle me); given the fuel trims, is there anything I should be looking at that I haven't done yet? Something I'm maybe overlooking that y'all can think of?

 

[TxGasRacer]

http://troubleshootmyvehicle.com/ford/4.0L/troubleshooting-P0171-and-P0174-page-1 http://easyautodiagnostics.com/ford/3.0L-3.8L/index-of-articles-2

 

[Keene1981]

That's the exact link I used to test the 02 sensors, then found the other tests on the site for the 3.0/3.8 and tried all those that appeared relevant. I'm at that end part where they say be patient... but the scan tool is on loan from AutoZone and every time I try to get the truck down the road, I make it about 3 or 4 miles and it dies on me again and I can't get it to stop the sputtering and dying until I let it rest until the next morning or so.

That is a great site, btw. Great wealth of home DIY testing knowledge.

 

[Keene1981]

Just got the upper intake pulled off. Upper gasket looks in pretty good condition; nothing to indicate a vacuum leak there.

And tested the fuel injectors with multimeter while down there.

All showing 12.0 Ohms resistence (give or take about .2 to the good or bad between the 6 of them).

Anything else to check while I'm in the guts of it?