Ok I was playing around with the obII reader that they use at the farm and I stumbled apon this.

IMG00892-20111218-1042.jpg

Anyone know about this, or seen this before.
also anyone know which part or parts to replace to fix this problem and where they are.

I'd imagine there on top of the gas tank but I could be wrong.

 

Is the check engine light on? Are you having any driveability issues? I would not be rushing out to replace any parts just yet. Also, here is what I found doing a simple search:

Tech notes
The P0004 is a generic code, but almost none of the vehicle manufactures use it. If you are getting this code, make sure you are using the correct code scanner for your vehicle's make and model.
P0004 Description
Fuel Volume Regulator Control Circuit High is the generic definition for the P0004; however your vehicle's manufacturer may have a different definition for the P0004 code

So it may not be anything.

 

see if it cycled, if your CEL ever illuminated, or if it illuminated then went back off, need more history, those scanners arent all the great to tell you the truth, your better off with that phone app TORQUE

 

The cel is on along with another code saying I have a bad cat. The truck runs very rich, you can smell it. I also get around 10 miles per gallon. Im thinking if I replace this part, it just might help my millage. I know many dakota owners that get 20 miles per gallon, and I'm trying to think whats makeing my dak different from theirs.

 

Hows the spark plugs and thtottlebody? R u to service? It couldjust be a o2 sensor

 

i would have the codes read by someone/something else first.