bad mpg what to do?

nothing happened.

 

That's the thing, "It runs good, it idles smooth, but there is no response." I will say this too, make sure that you have the PTO/fast idle enabled. If you're going to idle, the preset for the idle shut be 1,000 RPM.

"Could it be the turbo boost sensor?" It could be ANYTHING. A reputable shop will know what to look for. BUT, the first thing OP Needs to do:

1. Turn HP to max setting of 515 HP
2. Disable Progressive shifting

I'm telling you right now, You will not regret it. It is the cheapest thing you can do, then go and start looking around.

As far as the DPF clogging up and causing a loss of power, the engine knows when the filter is due for a regen and when the filter has reached its life cycle and requires manual cleaning or replacement. I friend who has one of these bought a used Columbia with over 500k miles on it, the DPF was just manually cleaned. A few months after owning it, the CEL came on throwing a code for high back pressure. DO NOT confuse that with "it wont generate." The truck would regenerate, but even after regenerating the back pressure was to high, causing the CEL to remain. The solution was to replace the DPF.

Certain things like an EGR valve can fail, but it may not be in the threshold to set a check engine light. I think my dad had around 200k on his Cascadia when he was getting awful fuel economy for about two months. The CEL eventually came on. As soon as that EGR valve was replaced, power and fuel economy were back. The only other problem he had in a 400k range with the truck was a temperature sensor on the DPF. It provided good service. At 6-7 MPG pulling a reefer OTR. He ran 75 MPH, the Series 60 gets better fuel mileage at higher RPM's, at least with his 13 speed at 3.58 rears I believe he had.

 

Sorry, my mistake, per my Detroit Diesel 07 engine operators guide, page 56.

http://s100.photobucket.com/user/tr...oads/CAM00013_zps132f0b35.jpg.html?sort=3&o=0

 

Well, I'll utilize the PM feature. The company I recommended does not just do ECM mods, they can do diagnosis and answer questions and steer the OP in the right direction. The OP is not looking to modify, nor am I suggesting the OP modify anything. For $300.00 from the last I heard, he can have his ECM looked at and diagnosed, get free advice, have settings changed to the OP's way and come back for free assistance in the future I believe. It's kinda unfortunate I can't post that information, as it can mean the difference between someone breaking even, starving, or simply going under. I feel you OP(original poster).

 

If the regen light is illuminated all you have to do is hold the switch down until it starts it's regen. The brake/clutch cycling is when you want to force it to do a regen.

 

That was my first photobucket attempt, I hope it works

 

I wonder if our friend has tried any of the simple and cheap suggestions that he was given and made progress with fuel mileage? Over the years I've noticed that many ask for answers to their questions and it seems few actually act on the hard earned wisdom that's freely shared.

I asked the same questions years ago and did what I was told. I started with the free stuff first, like changing driving habits, making sure my engine was healthy and reducing idle time. Then I went to the cheap stuff like an ECM tune and Fleet air filters. Now I'm saving plenty of money to spend on expensive stuff like replacing or eliminating EGR valves and DPF filters, Microblue, adding an APU, switching to low rolling resistance tires, etc... OR buying a Harley or new pickup OR planning for retirement...

 

You can do whatever you want to your truck, we just can't talk about those things here.

 

Yes you can, there are other places on the internet that you can find the information