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How To Remove Your 6.7 Cummins DPF and EGR

Author: SPELAB Mechanical Engineer (focusing on car modification for 10 years)

If you have a 6.7 Cummins diesel, chances are your truck has a Diesel Particulate Filter (DPF) and Exhaust Gas Recirculation (EGR). These two devices are designed to reduce emissions from the exhaust system. Still, they can cause problems for owners who want to modify their trucks with performance modifications such as turbochargers or nitrous.

For your 6.7 Cummins diesel to run at peak efficiency requires proper maintenance and care. This mainly includes regular tune-ups every 8,000 miles, ensuring that the DEF tank is filled correctly and replaced with new filters regularly. Many of the 6.7 Cummins owners have the Exhaust Gas Recirculation (EGR) and Diesel Particulate Filter (DPF) on their trucks removed for various reasons. This guide will show you how also to perform a DPF delete 6.7 Cummins and the EGR delete 6.7 Cummins.

Tools You Need for the Job

If you own a 6.7 Cummins, you probably know that the DPF and EGR systems are emission control devices. It's also one of the most hated features on your truck because it limits performance and causes premature wear.

The good news is that doing the DPF delete 6.7 Cummins and EGR delete 6.7 Cummins can be done relatively easily by yourself. You'll need some tools, but nothing too exotic or expensive.

• 10mm socket and ratchet
• 5mm socket and ratchet (valid for a DPF delete pipe)
• 14mm socket and ratchet (useful for an EGR delete kit)
• Torque wrench
• Socket set
• Pliers
• Screwdrivers
• Drain pan
• Disposable gloves and eye protection

Remove the Driver's Side Mudflap

The first step is to remove the driver's side mudflap. This will allow you to get in there, see what you are doing, and ensure you don't damage anything while trying to remove the DPF.

It can be challenging to see what you are doing with this thing on there. If your socket is short enough, you will need a 10mm socket or wrench and possibly a ratchet extension. You may also need an extension for your ratchet if it needs more reach.

The usual first step is to remove the two bolts that hold the Mudflap onto the truck bumper. There are two on each side; one at the bottom of each side near where it meets the bumper and one towards the middle of each side above

where it meets the bumper. The bolts are 10mm in size, so you will need a wrench or socket with that size opening, at least for removing your DPF system from your 6.7 Cummins engine.

After removing those two bolts on each side of your truck bumper, push down on each end to release the Driver's Side Mudflap.

Disconnect the EGR Tube

The EGR tube connects the EGR valve to the intake manifold and is on top of the intake manifold, just above the turbocharger. To disconnect the EGR tube from the manifold, you must remove a bolt and an O-ring from each end. You will need to use a 13mm wrench to remove it from its socket.

If you have an EGR delete kit installed, remove this tube from the bottom of your intake manifold. The tube should come out with minimal effort, but if it is stuck, use a rubber mallet or hammer to tap it out of place. Then you can pull it out of its bracket on top of the intake manifold and remove it by hand.

Remove the Downpipe on the Driver's Side

To remove the DPF, you will need to remove the downpipe from the exhaust manifold. This can be done with an impact wrench and socket set. Remove the nuts on both sides of the exhaust manifold, and then remove the downpipe from the 6.7 Cummins engine.

Remove the Downpipe on the Passenger's Side

You may also need to remove the downpipe on your truck's passenger side to gain full access to the DPF filter. The downpipe is an exhaust pipe that runs from your turbocharger to your tailpipe. You will know if you have a downpipe because it is typically made of stainless steel and has a large flange at each end. Once you find it, use a wrench and remove all of the bolts holding it in place. These are usually ¼" bolts but can vary depending on how old your truck is or what accessories you have installed. Once you have removed all the bolts, pull the downpipe off the truck and set it aside for now.

Remove the Turbo Y-Bridge

The y-bridge is a piece of tubing that connects the two turbos. To remove it, you need to unbolt the turbocharger from the exhaust manifold and disconnect all the wiring harnesses and vacuum hoses. You should also remove any bolts holding it down, which may not have been bolted down if you have an older-style turbo.

Remove the Coolant Hoses and Electrical Connectors

Reach under the truck and disconnect the coolant hoses by pulling back on them with a pair of pliers. Make sure they are disconnected before moving to the next step.

Next, remove the electrical connectors on the back of each valve cover by gently pulling them out with your fingers. Make sure you have a firm grasp on them before pulling as they are very fragile. If they break off in their housing, use a small flathead screwdriver to pry them out. This can be done by inserting it into the hole where they come out and gently prying it until it comes out.

Remove The Valve Covers

Use an Allen wrench or ratchet with socket extension to remove the six bolts holding each valve cover. You will only need to remove one bolt per head at this time, then put everything back together while you work on removing your DPF delete pipe & EGR delete kit system so that everything stays clean and organized.

Unbolt the DPF From the Truck and Pull it Off

The other step to DPF delete 6.7 Cummins is to unbolt it from the truck. This requires going under the truck on the driver's side, where you can easily see all of the bolts that hold the DPF to its bracket. Once you've unbolted them, pull the DPF off of its bracket.

Once you have unbolted your DPF from your truck, you will need to unplug all of your sensors from inside of it, such as your EGR sensor wire, oil pressure sensor wire, and any other wires that are connected to it inside of it once you had unplugged all of these wires, set your DPF aside for now and move on to replacing your EGR valve, which is located under where your turbocharger used to be before you removed it earlier in this article series.

Conclusion

The Cummins 6.7 diesel has an embedded diesel particulate filter (DPF) that needs to be removed if you plan on cleaning the rest of the system. The EGR will also need to come out or be modified. There is a lot of misinformation floating around the internet concerning this procedure, but this article has shown you the correct way to do it. With the DPF delete pipe and EGR delete kit, Undertaking the DPF delete 6.7 Cummins and EGR delete 6.7 Cummins system is not hard and can be done with essential tools and a bit of time.