Welcome to FTE. As a fairly new user myself I can say that this page has been a real help on some of the issues with my own truck.
I also wanted to update you guys. Since I cleaned my EPBS tube, my milage has rebounded nicely. Still not back to where I was but close enought to blame ULSD and winter driving (more 4 wheel and warm up times)

 

I've got to disagree with your conclusion here...No.2 diesel has about 130,000 btu per gallon in it. The process used to reduce the sulfur content down to 15 ppm removes between 1 percent and 3 percent of the btu value (from about 130,000 to about 127,400 using 2 percent btu loss). Every trucking company I know (Werner and Schneider, as examples of large fleets with a huge amount of data) are reporting 1-2% fuel mileage drop (for Schneider it is 0.14 mpg) on their fleet-wide average of 7 mpg. So on our trucks with a guesstimate of FTE members of 15mpg, we should be seeing in the -0.3 mpg decrease due to ULSD.

The largest factor in fuel mileage (and this has been repeated many times in research) is the driver. From the best drivers to the worst drivers the difference in mpg is about 30%! My old man use to notice this phenomena when I drove his straight-8 Buick ! In fact, Schneider reported no comments by their drivers on decreased fuel mileage...they only see it in the data from total fleet miles and gallons purchased. Of course, this wouldn't explain these large drops in mpg that we see here...because we are only looking at one person driving the truck. Want to hear something shocking - the 0.14 mpg decrease due to ULSD that Schneider has seen cost them an additional $8 million per year and that does NOT include the added cost of ULSD (which was about 10 cents per gallon)...this is strictly added cost due to lower mpg's.

 

I cant argue with the puter but I had the exact symptoms with mine and I pulled the connection to the ICP sensor and there was oil in the connection. I ordered a new one from e-bay and put it in and last weekend I went to Phoenix and averaged in the high 18's on fuel mileage, I didnt think that was bad running winter fuel and a dirty air filter

 

I'm doing my mileage the old fashioned way - with a pen and a calculator. My mileage has slipped to 10-11 in town. I've replaced the MAP and cleaned the EBPS and tube. I just did the cleaning so we'll see what happens. As for everything else, filters, oil etc. - its all been changed. It is strange that so many people are seeing such a drop. I haven't changed my driving style at all and yet BAM! mileage is gone...

 

Yee gads guys! After reading through this thread I'll be spending HOURS under the hood!

 

My mileage check was the old fashion way (Pen and calculator) my refering to the computer was the statement that he had his codes read and it stated Cps issue

 

I just refilled with ULSD (again) -- not really noticing any mileage hits. I got 15.5 mpg, all city driving. And that's after putting my foot into quite a few times after installing the Kwikfilter. On the interstate, I've been getting 16-17. Oh, this is in the south (Florida), so no winter blends here...

Joe
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2002 7.3L F250 XLT CrewCab ShortBed 2WD

 

tholt34. Does the stumbling only happen when the engine is cold? I have a 01 EX . And mine does the same thing . I have put 2 cps in mine and the motor still stumbles around 40-45 mph .As for fuel mileage im roughly getting 13 mpg. Havent been able to figure problem out. Dealership is stumped too. Im curious if its a transmission problem.My 01 ex is stalling out now when I switch from reverse to drive .

 

it would stumble when it was warm, one night when it did stumbled it finally threw a ses light and the code was for cps. Replaced it and it is running fine. i can tell my tranny is having problems and i am wondering if it might be why my truck is not getting the greatest gas mileage. i get somewhere around 14 to 15 in the city. i do a lot of stop and go driving though.

my truck has been throwing a 1670 code here lately but not all the time but the truck seems to be running fine. had a few people tell me it might just be brain farting and causing it to throw the code. where is the icp connector at on these trucks?

 

Here is the ICP sensor picture:

 

It's the fuel. Way to many people complain about the mileage dropping and have not changed their driving habits. I am a conservative driver and have not changed my habits. My truck is well maintained (some people say, over maintained), my mileage has dropped. Test, graphs, computerized reporting, means nothing to me, filling it more frequently with the same driving habits proves it to me.. Sorry but thats my feeling.

 

I gotcha. I was running 19-20 and sometimes more on the highway in the winter - but no winter blend, we're south of Houston. Now I'm running 17-18 on highway with same driving habits, never over 2k rpm. In town or towing is way worse.

I tend to agree that the only difference has been the fuel with the change to ULSD. I know that has been disputed and I'd love to be wrong but can't find any other explanation and too many guys are having similar experience. I'd love it if someone could give me a direction to follow that would regain my in town 14-16 mpg but so far, no such luck.

 

You could try Stanadyne in your tank. With Stanadyne you will notice an immediate differance in your trucks performance. The extra cetane will boost your MPG.

 

what is you EBPS???

 

Exhaust Back Pressure Sensor. Located sort of below your serpentine belt idler pulley.
Tom