Thanks Dave, I am so grateful for this forum and people who are willing to help

 

Let's start with the easy stuff.
You need to check for codes, since it is an '01, you can do the key trick, On, off, on, off, on, leaving it on the last time. Look in the odometer window and write down the codes that you see. If you see P dOnE, and E dOnE, you have no codes. If you have codes, post them up so we can help.

Next is to go have it serviced, oil change, fuel filter, air filter. While you are there have them check the fuel pressure at the VP-44(injection pump). Have them show you the oil filter, and fuel filter, this way you know that they were changed, or watch them change the filters. Also, if they will let you see what the fuel pressure is with the truck idling and at 2500 RPM. This needs to be above 14psi for both, otherwise you need a lift pump.

Start with these and then get back to us.

 

Ok so just did the key trick thing. This is what it said and in this order,
P PCU
p 1693
P Done
P ECU
P 0230
P Done
So now what does all that mean? Thanks!

 

Oh I was just looking at my receipt from July and I did have a new lift pump, map sensors and high PSI injection pump, and an ofi??? pump... (hard to read the receipt) put in it. Is it possible that my computer system didn't cleared and thats why these codes are showing up?

 

The 1693 is a companion code, so it is nothing to worry about. It means that there is another code stored.

The 0230 is the lift pump circuit out of range. This may have been left when they changed out the lift pump.

If you have access to a code reader, you need to clear all codes. Or you might go to an auto parts store and ask them to read all the codes and the have them delete them. Drive it for a few days and see what codes come back.

 

And as a last resort, a locking fuel cap helps improve fuel mileage.

 

Locking fuel cap... I think you might be on to something, lol. Ok so I drove it today and filled it up again... got 18MPG. I think the problem was my trip odometer... Thank you everyone for your help! I'm still wondering about the codes... I called autozone and they said they can't erase them. Next time I take it in for a tune-up I'll have that checked out. I'm also towing on a long trip this weekend so I'll see how that affects my MPG... Thanks again

 

How many miles are on the truck? This will help things. Like the other boys said get the fuel filter changed. If the truck has alot of miles on it you should get the overhead run (valves adjusted) Just be carful who you take it to. i would take to a semi truck shop to have it done alot of dodge dealers arent to great with the diesel side of things. I would bet theirs nothing wrong if you were trully getting 5mpg you would be havin some really bad drivablity problems unless you have the truck moded out the ying yang. the edge box should help your fuel mileage unless you drive like a crazy deranged person lol.

 

The main reason for their policy is that some people like to erase all their codes before trying to sell a straight up lemon.

AutoZone can't erase the codes as part of their policy, however you might be able to get them to get the code reader to the point of erasing and just push the final button yourself. I have had a rep do that for me twice before.

On another occasion at a different AutoZone, they ran my codes and I asked him to delete them. He said he cannot and left me with the machine. It was easy to figure out if you watch him when he does it. I found my codes and deleted them myself.

All in all the cheapest way to get your codes deleted is to just go to different parts stores until you find someone who will stretch policy a bit to help you. I'm sure you can give them a wink and a perdy smile and be on your way.

 

lol - nice