My fuel mileage has dropped significantly recently. I had my codes ran several times before the tranny swap and here's what I got: A torque converter code(no more TC so no more code), some CPS codes(blah blah blah- fixed), and a P0472 which is Exhaust Pressure Sensor Circuit Low Input. Now for the questions.

Is that referring to the exhaust back pressure sensor attached to the HPOP? If so, I cleaned it and the tube as well as possible a couple months ago and still threw the code again. Could a problem with it affect my fuel trim thus decreasing fuel mileage? On page 10 of this link there are some diagnostic things but I don't even know how to translate it. http://www.motorcraftservice.com/vdi.../DOBDSM971.pdf

 

Wire the EPBV back and unplug it, see if that makes a difference.

 

Alright I'll give it a go. What do you mean by wire it back? And unplug the sensor at the top of the HPOP?

 

The plug for the sensor is right by the turbo pedestal on the drivers side.

 

From what I noticed on mine, that is an indication that the EBP sensor tube is blocked.

And I also discovered some spray brake cleaner does an excellent job cutting the soot, then some shop air to blow it clean.

No more code.

 

Hey Dave, where is that tube at? I know I read about it before but I can't remember. I'd like to check mine too.

 

Yea, I keep forgetting about that thing you guys are talking about.

I've never had to mess with mine, Knock on wood.

 

If you pull off the black plastic cover that is over your fuel bowl, GPR, HPOP, etc you can access it. It is a small metal line that runs from the EBP sensor and snakes between the alternator and HPOP down to the exhaust.

I've pulled and cleaned mine before. I used brake parts cleaner and weed trimmer line. It seemed to clean it really well but I still had the code afterward.

 

I'm tempted to clean that now. haha.

 

It's not terribly hard at all. You can also pull the sensor and do the same with it. If the line is dirty then chances are the sensor is too but be kind of ginger with it because it's not cheap.

 

Hey where can I buy one of these EBP sensor tubes?

I went out and looked at mine after reading this to realize it's cracked at one of the bends.

 

That's what I was thinking.

 

Well I posted some time ago some pics of the sensor and in one of them you barely could see the tube, but it could be in front of the HPOP or between it and the alternator, both goes down to the exhaust in pass. side.


You can buy it in Ford dealer. IIRC Neal has the # part. Ill look for it.

 

Here are a pic of the tube with a hole and the # part, but be careful because for the sensor there are two numbers acording with the model year:
Exhaust Back Pressure Sensor<O</O
(Ford) F4TZ-9J460-A (94-96; mounts on bracket above oil reservoir)
(Ford) F7TZ-9J640-AA (97-up; may mount like earlier models, later in front of reservoir)
<O so I thik that the tube also has different # part, all depends if goes in front or back of the HPOP. The number in the pic if for 97-up (in front), stolen from Neals pics.</O

 

Well after some digression I'm still curious how to wire the EBPV back? Also, what all goes into gutting it and have yall found any negatives to doing it?