Diesel Tuner's Blog

How the Ford 6.7L Powerstroke DPF & Exhaust System Works

Posted by Paul Wilson on Oct 18, 2017 9:29:00 AM

DPF, EGR SCR, DEF, What does it all mean?!?

Before you throw an exhaust on your 2011-2016 Powerstroke, at least understand what the emissions equipment is and how it works.


Sure there are plenty of guys that had to delete their truck because they had an issue with the emissions equipment.  But there are also a lot of guys that have never had a problem with it.  Just imagine if you could get the same or ever more power and performance from a DPF, EGR, DEF equipped truck as you could from it's deleted counter part.  If you understand how the emissions equipment works, there is less of a chance you will need to delete it. 



NOx - Nitrous oxides, is the nitrogen dioxide and nitric acid. NOx emissions have been blamed for all sorts of bad things happening in the environment, Nitrous oxides are produced when combustion of diesel fuel occurs.  This is because nitrogen gas is a naturally occurring element in atmospheric air.

Diesel Particulate Matter - Also known as Soot or Smoke.  Diesel Particulate Matter is unburnt fuel projected into the atmosphere.  Most commonly this is from either low quality tuning or a mechanical failure with your diesel truck.  

Carbon Monoxide - Carbon monoxide is a highly toxic gas that is without color or smell.  This is a byproduct of burning fuel during the combustion process.

Carbon Dioxide - Carbon dioxide or CO is a result of combusting various hydrocarbon compounds that make up petroleum based fuels, including diesel.  Carbon dioxide is a "greenhouse gas" and CO2 emissions are a leading contributor of global warming.


Exhaust gas recirculation (EGR) is a technique employed to reduce NOx emissions and reduce cylinder temperatures.  It is made up of a valve, cooler, and monitoring equipment.  Basically, it allows exhaust gas to be used as a portion of the intake air.  

Many horror stories exist about EGR failures.  Especially in the previous 6.0L and 6.4L models.  However, the launch of the 6.7L Ford introduced anextremely functional EGR system.  Equipped with a more robust cooler and a better understanding of when and how much EGR to use has created a system that can last.


Stringent EPA regulations forced the hand of manufacturers to produce diesel pickups with lower emissions output.  This meant inventing a system that treats the exhaust after combustion, hence the name Exhaust Aftertreatment.  It includes many working pieces to achieve the rules set by the federal government.  

Diesel Oxidation Catalyst (DOC)

The diesel oxidation catalyst, or DOC, produces heat for DPF Regen while converting hydrocarbons and carbon monoxide into water and carbon monoxide.

Diesel Particulate Filter (DPF)

The diesel particulate filter, or DPF, filters particulate matter (soot) from the exhaust and muffles the sound of the exhaust. With the electronic monitoring of the 6.7L Powerstroke, the DPF has become very efficient and effective.  

Regeneration Process (Regen)

Regen is the process of burning off the built up diesel particulate matter (DPM) in the diesel particulate filter (DPF).  There are three regen strategies for the 6.7L Ford, passive, active, and manual.  

ford 2015 tuning.jpg

One of the requirements for any regen to start is the exhaust gas temperature must reach between 950° and 1050° F.  This is hot enough to burn off the built up soot.   

Passive regen happens when operating conditions, most notably exhaust gas temperature, reach or exceed the minimum range in which regen can occur. This mostly goes on while towing heavy or working the truck hard.  A driver will most likely not even know it is going on. 

Active regen is when the truck sends raw fuel into the exhaust in an effort to raise exhaust temperatures high enough to burn off the soot in the DPF.  While this will dramatically impact the instant display for MPG's it makes only a small impact on the trucks total efficiency over a tank of fuel.  In our testing, some trucks with deleted emissions actually got worse fuel mileage than stock.  In other words, active regen is not really using a lot of fuel to achieve it's goal. 

Manual regens should be avoided.  They can be initiated by a technician through the vehicle's on-board diagnostic system or with some aftermarket monitors if totally necessary.  A manual regen is essentially an active regen cycle that is manually initiated.

Selective Catalytic Reduction (SCR)

The selective catalytic reduction (SCR) converts NOx into nitrogen gas and water by using diesel exhaust fluid (DEF).  The system greatly lowers the number of active regens and the amount of EGR required.  Obviously, this positively impacts fuel economy and adds to the projected longevity of this platform. 


Calibrated Power has put countless hours into researching the 2011-2016 Powerstroke platform and it's emissions equipment.  Our tuning will not increase regen frequency or decrease the life expectancy of your truck. 

If you would like to talk about what your options are for emissions equipped tuning, click the button below and fill out the corresponding form.  One of our knowledgeable staff will follow up to discuss your specific situation and answer all of your questions. 

Get Custom Ford Tuning


Topics: Emissions, Emisssions Intact Tuning, Emissions Intact, 6.7L Powerstroke, Emissions Equipped, Ford, 2011-2016 Ford 6.7 Tuner, Ford 6.7, Powerstroke Tuning, Power Stroke