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Discussion Starter · #1 ·
I got an 08 6.7 with auto trans...(just blew) anyway it has a h&s mini maxx with 5 inch tbe and sinister diesel egr delete. When I hammer down on it I get lights like fuel rail pressure too low and the relief valve popping prematurely. I just did my oil change and got on it yesterday and got low oil pressure now. Another dumb thing that happens is even if I'm driving normal a perform service light will come on and a code won't show up with it the truck will just say perform service??? I'm wondering what you guys think like maybe a weak lift pump or fuel pump ect... I'm not sure I think I want to shim the relief valve anyway but I should probably tell you guys I usually drive with the tuner on performance mode (200hp) do you think the lift pump is fine and maybe it just can't get enough because the motor needs more obviously when it's on performance mode right? Tell me what you guys think about the codes and all!
 

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What are the codes?
I have p0087 and p1011 happening on mine, not sure if the lift pump is gone or not in mine.


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everything on the truck was designed to run at 350 hp, not at 550. (if you're running the mini maxx on the 'hot' tune, its 175 hp actually). And everything on the truck was designed to operate at stock truck height, not with a 6" lift. those things change everything.

you can't throw 50% more power at the engine, and expect everything to work perfectly without modifying your trans, fuel supply, air supply, and possibly suspension.

If you haven't installed head studs yet, you'll need those, or chances are your head gasket will blow with that high tune, and hammering on it.

If you want to hammer on it, and have your truck last, i suggest you invest into a billet trans, head studs, FASS or AirDog pump, and upgraded cp3, to get started.
then injectors, turbo, etc..

gotta pay to play. :$:
 

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LIFER
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Change your ccv filter, do a ccv breather mod. And shim the rail. That should clear your codes and perform service.

The above mentioned mods are an eventual necessity as well. If you beat on it, I recommend studs, FAST.
 

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Change your ccv filter, do a ccv breather mod.
Thanks for that info, didn't even know of that existing lol I'm in a similar situation as the OP but I just run stock tune on the H&S and find the stock power output more then enough pulling power.
I'm getting the low fuel pressure code and map sensor code, last major part is upgrading to a fass pump, but was hoping that running stock tune didn't require it.




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LIFER
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Change your fuel filter as well. You should jot be geting low fuel pressure codes. Low rail pressure yes.
I ran hot damn 225 with an mp8 and a shimmed rail for a small stint on stock fuel with no codes. I dont recommend this combination by the way.
 

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Did filter change, shim kit and then FCA change
And still get the p0087 + p1012 codes, with those codes comes injector knock at low rpm, no loss in power, no smoke, no fuel in oil. And those codes used to come and go, one day truck runs flawless next it's popping codes and knocking, seemed to gradually get worse


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I just bought a 2014 Dodge Cummins 6.7, I went to hook up my utility trailer today and on my screen it said " no trailer connected" I took it to the dealership and they could not figure it out. They reset everything checked all the wiring and couldn't find anything. They called Chrysler and they did not know what it could be. I took the truck to the Uhaul shop and connected it to other trailers So I ruled out the fact there was anything wrong with my trailer. Same thing happen it stated "no trailer connected". But the lights on all the trailers work. The dealer is working on what the problem could be. But for the mean time they will order a new trailer brake and replace to see if thats the problem. They had the computer hooked up to it and did not find any malfunction short or blown fuses. Can anyone help
 

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I got an 08 6.7 with auto trans...(just blew) anyway it has a h&s mini maxx with 5 inch tbe and sinister diesel egr delete. When I hammer down on it I get lights like fuel rail pressure too low and the relief valve popping prematurely. I just did my oil change and got on it yesterday and got low oil pressure now. Another dumb thing that happens is even if I'm driving normal a perform service light will come on and a code won't show up with it the truck will just say perform service??? I'm wondering what you guys think like maybe a weak lift pump or fuel pump ect... I'm not sure I think I want to shim the relief valve anyway but I should probably tell you guys I usually drive with the tuner on performance mode (200hp) do you think the lift pump is fine and maybe it just can't get enough because the motor needs more obviously when it's on performance mode right? Tell me what you guys think about the codes and all!
think it has anything to do with the guy in your avatar:buttkick:???
 

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Discussion Starter · #11 ·
So you guys think shimming the rail and installing an air dog pump and an upgraded cp3 will help? Oh and studs ;)
 

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LIFER
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Why don't you recommend the mp8 and h&s tune?


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I dont reccomend it with the 225. Because most everyone that will try it has a stock turbo, no studs, and no rail pressure gauge. On top of that rail pressure is uncontrollably high, and asking for broken parts. Custom tuning is a much better option. However, with supporting mods, and a suitable whistle to clean it all up, it works well. I liked it on the wild setting, the most on the regular 175 no turbo tunes.

I have mcc, and iam curious as to how it will cooperate. I took it off to sell it, but might put it back on for a little bit to see.

I know ryan, put an atomizer on his truck, temporarily for a dyno run on top of his custom tuning, to see if it made a difference, and from what I gathered, it made a noticeable difference.
 

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Discussion Starter · #13 ·
I mean I ain't trying to make a drag truck but I'm sure you understand how annoying it is that when you got on it you throw codes like low rail pressure ect... I just don't know where to start I'd like a new pump, cp3 and shim kit but you guys are the experts I'm just a pipeliner who needed a diesel and now wants to make it fast lol! And I'm new at all this anyway
 

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Discussion Starter · #14 · (Edited)
I appreciate all your input fellas!
 

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LIFER
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Just go with the shim kit asap. Should solve your issues. If not then you know to upgrade the pumps. Start with the cheapest solution first. Either way the shim kit is not wasted funds. Easy to do and will allow you to grow down the road.

Oh yeah, studs, now. Not optional.
 

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Discussion Starter · #16 ·
1barn3s you are a funny dude! Thank you very much man! Is it hard to install the cp3 pump and the lift pump? Is the lift pump in the fuel tank? Are head studs easy to install? Could I get 50hp injectors also?
 

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Why don't you recommend the mp8 and h&s tune?


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the H&S tune already raises the rail pressure in the tuning. the mp8 does that as well. raise the rail pressure to high and it'll empty your pocket book in a hurry. Injectors are 400 a piece from Cummins. let alone the rail and everything else you could mess up.

additionally, even if you don't over pressurize to the point of catastrophic failure, to much pressure on stock injectors, will lead to premature failure.

if you're not happy with H&S box tuning alone, get MCC. Contact davematthews on here for help with that or kraezuen (hope i spelled that right ryan)
 

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LIFER
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You can do whatever you like. But if you run those injectors, I highly recommend custom tuning as well. And dont spend the money on 50's, go 100's and have them tuned down to 50's. That way down the line when you get a bigger pump you can grow with it. Gonna need a bigger whistle though if you up your fuel.

As for the pumps, they're not to difficult, just a little time consuming. Do your homework and take your time on the install. The aftermarket lift pump will not be located in the tank, and the oem one will stay in there, i recommend a sump or a jeep liberty canister mod if you cant afford the loss in clearance. To go along with your lift pump install.

You should get custom tuning first, it will really wake your truck up.

Goodluck though, and be warned they still havent found a cure for the hpbug.
 
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Discussion Starter · #19 ·
One more question you say I should have custom tuning? I think I do... I have a mcc tune from hardway performance and it goes stock tow street performance isn't that "custom"
 

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LIFER
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Yess mcc is custom tuning, and ryan knows his stuff. You have good tuning. Which is probably why you haven't blurb a head gasket yet, but don't push your luck.

Wait for it...

Its coming...

Studs.
 
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