Egr

[RDBuck]

Just bought an 07, 54000 miles- June build. Traded my 02. Nice truck but mpg at 10-12 is unreal. Reading posts it seems the quickest thing to do is unplug the EGR. How much gas is recirculated by the EGR? Is the crankcase vent connected to the EGR and if so what happens to that pressure if EGR is blocked? Love the auto trans. !l

 

[EricBu12]

No, what happens is the exhaust gas is recirculated back to the intake to be re-Burned this also uses some fuel in an extra fuel event... . Crankcase vent is separate system.

So does the new truck have big tires and lift and such? Also driving habits help. . my 09 is stock and I try to coast as much as possible. . i get around 14 average. . There is also a lot of electrical things to do to do a delete. sensors and such. some have just unplugged it but the CIL light comes on.

 

[LNaugle]

it is not a good idea to just go unplugging things. do u have emmisions where you live. we dont and my dads truck gets 19-23 mpg depending... .

 

[KLauber]

I unplugged and instantly got better mileage. Eventually deleted (and stored) the 'stuff' for about 15 in the city and 20 on the highway.

 

[Bob4x4]

No, what happens is the exhaust gas is recirculated back to the intake to be re-Burned this also uses some fuel in an extra fuel event... . Crankcase vent is separate system.



So does the new truck have big tires and lift and such? Also driving habits help. . my 09 is stock and I try to coast as much as possible. . i get around 14 average. . There is also a lot of electrical things to do to do a delete. sensors and such. some have just unplugged it but the CIL light comes on.

The egr does not get reburied... . it is to be considered an inert gas and displaces 02 that does aid the combustion process

 

[Bill Stockard]

A simple explanation of what EGR does in one paragraph:



"Exhaust Gas Recirculation:



Exhaust gas recirculation, also known as EGR, is a technology that is not specifc to the diesel industry. EGR systems have been used for years in both diesel and gasoline powered vehicles because they help to lower greenhouse gas emissions. In a diesel, the primary function of the EGR system is to lower the amount of Nitrous Oxides (NOx) produced by the combustion of diesel fuel. A portion of the engines exhaust gas is recirculated into the engine and combusted again. This lowers the amount of excess oxygen and lowers peak combustion temperatures. Since NOx formation occurs much faster at high temperatures, the EGR limits the generation of NOx. NOx is primarily formed when a mixture of nitrogen and oxygen is subjected to high temperatures. Despite the reduction of NOx, Exhaust gas recirculation systems have negative effects on performance and fuel economy, and other exhaust treatments are necessary because EGR systems increase the amount of diesel particulate matter produced by the engine. "



Bill

 

[Bob4x4]

, Exhaust gas recirculation systems have negative effects on performance and fuel economy, and other exhaust treatments are necessary because EGR systems increase the amount of diesel particulate matter produced by the engine. "



Bill

Because the 02 depleted gas does not add to the combustion process

 

[Bill Stockard]

Because the 02 depleted gas does not add to the combustion process

Yep, with less O2, there is less peak combustion heat producing less NOx, but the trade-off is more particulate matter (soot-unburned hydrocarbons) in the exhaust stream from the (increased) incomplete combustion.



Bill

 

[RDBuck]

If I'm understanding this right- I unplug the egr, get better mpg due to a better burn of the fuel and put less soot downstream thus fewer regens and less chance of a plugged dpf?

 

[HBarlow]

DPF?

Is your truck an '07 5. 9 or an '07. 5 6. 7?

5. 9s don't have a DPF.

If its a 6. 7, simply unplugging the EGR will set codes and cause a CEL on the dash. Some conditions that set a CEL will ultimately cause a limp home mode with reduced power but I don't know if disabling the EGR will cause it.

 

[RDBuck]

Truck is a June build 6. 7. Has all the latest flashes. Completely stock. Been running Cummins power in many applications for 40 years. This is the third worst economy from an engine I have ever had - the first two being a 1938 Buick Roadmaster (straight 8)and a 1961 Lincoln Continental!

 

[HBarlow]

I think you'll want to do some reading on the subject before you unplug the EGR valve.

There have been a number of threads on the subject in the last year or two. Basically speaking, in order to disable the EGR function you'll need a magic black box like a Smarty to erase the code to allow running without it and may need a blank flange or kit to block it. To disable the DPF requires another kit with hard parts.

Its not simple or cheap. Some have done it and can offer specific information and advice that I'm only generalizing.