I have successfully fixed my IMRC problems and got the truck from 12 codes down to 2. The problem I'm having now is the codes it's throwing are P0171 system too lean And P0455 evaporative emissions system leak detected. I can think of a few things but I'm pretty stumped. By the way where does that little gray vaccum line on the pssanger side go?

 

After engine is warmed up, unplug the wires from IAC(idle air control) valve, RPMs should drop to 500 or engine may even stall, either is good, if RPMs stay above 700 then you have a vacuum leak causing the lean code, with IAC disconnected it can be easier to find.

And the "little gray vacuum line" may be it so plug it and see if idle drops during above test.

It is a hard plastic vacuum line?
These are often used for the Vacuum reservoir(round black globe) or to the air cleaner box.

Since you also have an EVAP system code "little gray vacuum line" may be part of that vacuum system, there should be a vacuum diagram on the rad support.
EVAP = emissions system, and uses engine vacuum to suck air out of the fuel tank when engine is running, this prevents gas fumes from polluting the air, pressure code could mean that vacuum line is part of the system, or it could mean gas cap is not on tight or is leaking air, fuel tank needs to be sealed or you will get EVAP code

 

Thanks man. I'll check that out right now . I am starting to think I need to replace the fuel neck though. That little flapper over the fill hole is not there. Thanks though.

 

Alright. She passed the IAC test . I'd like to check my EGR pressure feedback sensor but I can't find the damn thing

 

I know where it is on the V6 but I cannot find it on my 2.3
Any clues?

 

Find the small hose on, or very near, the EGR valve's tube to exhaust manifold, follow it back to DPFE.
These usually get water in them from exhaust humidity, you can try to dry them out but.............they usually need to be replaced.
And the DPFE is one of very few items on a Ranger that should NOT be replaced with another Motorcraft(Ford) part, use 3rd party, they seem to last twice as long.

DPFE sensor is not related to P0455 code


Lean code means computer is adding more fuel than the MAF sensor data would indicate is needed.

MAF sensor data is the volume of air coming in to the intake
computer then calculates the 14:1 air fuel ratio based on that air volume
computer adds that amount of fuel via the fuel injectors
computer then gets O2 sensor data about oxygen level in exhaust, if there is too much oxygen(lean) then computer adds more fuel, too little oxygen(rich) and it adds less fuel
This is called the Fuel Trim, 0 trim mean computer is adding the calculated 14:1 ratio of fuel and O2 is showing all is well, just the right amount of oxygen in the exhaust
-1 trim means computer is adding less fuel because there was not enough oxygen in exhaust, +1 means computer is adding more fuel because there was too much oxygen in the exhaust.
Normally fuel trim will run between -10 and +10, when a trim gets up to -20 or +20 computer will notify driver by turning on the CEL
P0171 mean +20 has been reached, engine is not actually running Lean, computer is adding the extra fuel, computer is just letting you know there is something wrong, either with the MAF data, the O2 data or the computer itself, the calculations are not adding up.

Dirty MAF sensor will under report the air volume, so computer's fuel calculation will be low and it will have to add more fuel.
Leak in exhaust manifold will suck in air, O2 will see that as more oxygen(lean) computer will add more fuel.

Vacuum leak of course, but this leak can be around the MAF sensor so while it is not technically a "vacuum" leak unreported air is being sucked in to intake so MAF data would be off.
O2 sensors are spec-ed to last 100,000 miles, they work by using a chemical reaction, like a car battery, so they do wear out when the chemicals get used up, just like a car battery.

 

Awesome. Thank you very much. I didn't want to replace the MAF sensor but there is a crack in the cover which is crudely sealed. That may be where the extra air is coming from. Everything else seems to be right but I still can't find the Damn PDFE sensor. I think it is behind and under the manifold judging by where the hoses run. I guess I'm gonna have to fork out that $100 bill for the MAF. Thank you very much for you help.

 

Wrecking yard, then clean it, there are hundreds of 2.3l duratecs in wrecking yards, in cars mostly, and as far as I know they would use the same MAF sensor, although the housing might be different.


2.3l duratec was used in these vehicles

2003–2007 Ford Focus
2004-2007 Mazda Axela/Mazda3
2003-2008 Mazda Atenza/Mazda6
2005-2008 Ford Escape/Mazda Tribute/Mercury Mariner
2002-2005 Mazda MPV
2006-2009 Mazda Premacy/Mazda5
2006-2009 Ford Fusion/Mercury Milan
2010-BAC Mono (developed by Cosworth)
2010–Thoroughbred Motorsports "Stallion" Trike
2001-2010 Mazda B2300
2001-2011 Ford Ranger


It might not be your MAF sensor though, but if it is cracked..................might be