CEL PO171 & PO174 too lean banks 1 & 2.

[Jerry Gerner 2]

Ok so I had the CEL come on yesterday when my after I filled up the tank. Thinking it was the PO442 code again I left it go until I was done with the brakes today. Went to Advance Auto and used their code reader and PO171 & PO174 show up, I replaced the gas cap for the other code, cleared the codes and the light hasn't came back on after driving all day. Kepp in mind the truck isn't hesitating, misfiring, anything. There is a smell to the exhuast so I'm thinking I just got bad gas andit thru the CEL. ???

 

[EddieS'04]

The codes point to the DPFE sensor....

 

[swshawaii]

Category

OBD Codes

Frequently Asked Question

OBD Codes P0171 and P0174



Answer

This code is a common code to the Sport Trac. It is normally the elbow that is located under the throttle body. It tends to crack on the bottom and needs to be removed to examine it. You can replace it with a small piece of heater hose that is 5/8 inch. But heater hose is a quick fix. The hose will soften and collapse causing other problems. We recommend you purchase a PCV elbow or the replacement part form a dealer.



Last Updated

12/30/2007

 

[Jerry Gerner 2]

Does anyone have a picture of the DPFE sensor? I searched and saw postings talking about that but not sure which one it is. Does it have a round cylinder top and two stubes on the bottom?

 

[Jerry Gerner 2]

I just googled the sensor, it's the one just to the left of the oil dipstick, correct? It has two tubes in the bottom and a pigtail connector on the rightside?

 

[Jerry Gerner 2]

Eddie, how do I test the sensor? Also I have my wife's '99 Mercury Sable that I'm parting out, I looked at the sensor on that and it looks exactly the same but when I called Advance Auto they had two different part #'s for the two, think it will work??

:banghead:

 

[Tom Schindler]

Jerry,



Those are lean codes, not EGR codes. It is the cracked elbow and NOT the DPFE sensor.





Tom

 

[Jerry Gerner 2]

Elbow's good but I'll take the whole tube off tomorrow and double check again. I thought those codes were for the O2 sensors or PCV elbow. I miss driving Pre-'75 vehicles.

:banghead::cry:

What else could it be if it's not the elbow??? Like I said the truck doesn't stutter, misfire, anything, you can smell a difference in the exhuast though.

 

[EddieS'04]

Jerry, I screwed up. I jumped in with too quik of an answer. Those codes mean you are getting unmetered air. The O2 sensors are reading lean burn.

 

[swshawaii]

Wow Eddie, you're human after all. LOL :grin:

 

[scott degroot]

I have to disagree with you Eddie



The codes mean that the engine is running lean...it could be unmetered air but it could also mean not enough fuel. Granted that 9 times out of 10 it is a vacuum leak/unmetered air that causes it.



If you can smell a difference in the exhaust then you may want to have a look at your mass airflow sensor to make sure that it is clean.

 

[Dominoelover thegamenotthepizza]

Jerry here is a picture of the sesnsor.



The picture is from Todd T's library





He also has a picture of the EGR sensor in there.



http://www.mysporttrac.com/shared/memberlib.asp?VIEW=8893

 

[Jerry Gerner 2]

I'll clean the MAF, IAC and check everything. It's been getting colder and I have the CAI on it, might be affecting it. In the last two fill ups I've gotten 40-60 mpg not sure if it's the RT ypipe and cat finally breaking in but it's been really nice. I'll keep you guys posted on what I kind, thanks.

 

[Kevin Lang]

In the last two fill ups I've gotten 40-60 mpg

What? That's more than a Prius in the city.



Even if you went through with that hydrogen enhancement that iirc you were the one posting about, that's only a 10-15% mpg @ most improvement, which is no where near 60 mpg.



Hell, 60 mpg is 1350 miles per tank in the ST.

 

[Jerry Gerner 2]

Sorry, I ment to the TANK, my bad, damn spellcheck put it as mpg.

 

[mookie]

In the last two fill ups I've gotten 40-60 mpg...I ment to the TANK,....

40-60 miles to the tank!!! That's like 1.7-2.6 mpg!

 

[Jason McKinnon]

Wow, that's from one extreme to the other...



On a related note, I have one of the old SCT tuners, and recently flashed back to stock in preparation for my emissions check (doesn't seem to work with the alternate program installed). Since then, I have started getting a CEL indicating a P0171 (bank 1 lean) code, but not a P0174. Some may remember, I recently posted a problem in which my A/C stop blowing through the main vents when under moderate to heavy acceleration. Given these problems, I'm guessing that it's a vacuum leak somewhere. It's not the elbow that always cracks as I've replaced it before and that was the first place I looked. On my other post, someone suggested the vacuum reservoir/canister/ball thing... I've looked a bit, but cannot seem to locate this device. Can anyone tell me where I would locate that on an '01 trac (build 2)? I really need to get this fixed so that I can get my emissions done and get my tags by the end of the week...



Thanks in advance for any help,

JayMcK