2007.5-2009 Dodge 6.7L Cummins Exhaust Parts

The exhaust system on the 2007.5-2009 Ram 6.7L Cummins

When the 6.7L Cummins replaced the 5.9L in mid-2007, the exhaust became a full emissions system. Exhaust leaves the head through a cast-iron manifold and spins the Holset HE351VE variable-geometry turbo. From the turbine outlet, the downpipe feeds a diesel oxidation catalyst (DOC), a NOx adsorber catalyst (NAC) and a diesel particulate filter (DPF), while cooled EGR handles part of the NOx job at the engine. Behind the DPF is the tailpipe section. There is no SCR and no DEF tank on these pickups; SCR did not reach Ram pickups until 2013. When the DPF fills with soot, the engine computer runs an active regeneration, injecting extra fuel to raise exhaust temperature to at least about 1,112 degrees F and burn the soot off. Normal driving alone does not get hot enough, often enough, to keep the filter clean. The turbo also doubles as the exhaust brake, closing its nozzle to build backpressure.

What fails and why

DPF loading. This is the signature problem of the 2007.5-2012 6.7L. Without SCR, the engine runs a richer mixture that makes less NOx but significantly more soot, so the filter loads quickly. Watch for frequent regens, an 'exhaust filter nearly full' message, derate, poor fuel economy and lost power. It is worst on trucks that make short trips or idle a lot, and it can show up at any mileage. Chrysler and Cummins issued several reflashes for it.

Cracked manifolds and broken studs. The cast manifold can crack and its studs can break as heat cycles and miles add up, and broken manifold studs turn up in owner reports on 2009 Ram 2500s. Symptoms are a tick at cold start that fades as the engine warms, soot streaks at the manifold or turbo flange, and lost boost.

Exhaust sensors. Owners of 2009 Ram 2500s report O2-type exhaust sensors burning out more than once, with a check engine light, sensor codes and regens that fail. Treat that as an owner-reported pattern rather than a documented defect, and read the codes before you buy a sensor.

Stock replacement vs. upgrade

Start with what is free. Let a regen finish instead of shutting the truck off in the middle of one, keep idle time down, and run low-ash CJ-4 oil. Those habits are the no-cost way to extend DPF life. For the tailpipe, a DPF-back system (MBRP calls its version filter-back) replaces only the pipe behind the filter. The DOC, NAC and DPF stay where the factory put them, and the kits fit every pickup cab and bed length. For the manifold, new gaskets and hardware fix a broken stud, and a replacement manifold fixes a crack. The upgrade is the ATS Pulse Flow manifold, cast in high-silicon-molybdenum alloy with about 30 percent more flow area and built to resist the cracking seen on stock castings.

What we carry

• DPF-back systems: MBRP filter-back systems in 4-inch and 5-inch, in Armor Lite, Armor Plus and Armor BLK versions.
• Mufflers, resonators and tips: MBRP universal mufflers and diesel resonators, plus exhaust tips from MBRP, Pacific Performance Engineering and Mishimoto, and Mishimoto heat wrap.
• Manifolds and hardware: the ATS Diesel Performance Pulse Flow manifold, a BD Diesel replacement manifold with gasket and bolt-and-spacer kits, stud kits from Gator Fasteners, Fleece Performance Engineering, Mishimoto and PPE, a stainless bolt kit from XDP, and Dorman manifold bolts.
• Gaskets: MAHLE manifold, EGR, flange and catalytic converter gaskets and head sets, the Cummins genuine upper engine gasket kit, and a Dorman EGR gasket kit.
• Sensors: XDP O2, exhaust gas temperature (EGT) and exhaust backpressure (EBP) sensors.
• Exhaust brake and clamps: a BD Diesel remote-mount exhaust brake and V-band clamp.

For other trucks and more brands, browse our full exhaust department.

Fitment notes

DPF-back kits are built for the pickup. The 3500 chassis cab routes its exhaust differently, so confirm you have a pickup, and check single rear wheel versus dually tailpipe exit before you order. A replacement manifold for the 6.7L is a different casting from the 5.9L, so order the 6.7L part. Studs, bolts and some gasket sets are listed across both engines (1994-2018 or 1998.5-2018), which is fine as long as your truck falls in the range. Many listings read 2007.5-2012 or 2007.5-2018 because the 6.7L carried into later trucks, but some parts are narrower, such as the MAHLE F32901 flange gasket at 2007.5-2010. These trucks were sold as Dodge Ram. Verify by VIN when a range looks close.

Frequently asked questions

What does a DPF-back exhaust replace on a 2008 Ram 2500?

Only the tailpipe section behind the diesel particulate filter. The DOC, NAC and DPF all stay in place, so the factory emissions equipment is untouched. MBRP's filter-back systems for this truck are listed for 2007.5-2012 6.7L pickups and fit all cab and bed lengths.

Why does my 2007.5-2009 6.7L regen so often?

These trucks have no SCR, so the engine runs richer and makes more soot, and the DPF loads faster than on 2013 and later Rams. Short trips and long idle periods make it worse. Let regens finish, limit idle time and run low-ash CJ-4 oil. If you are seeing derate or filter-full messages, have it scanned, since Chrysler and Cummins released reflashes for this.

How can I tell if an exhaust manifold stud is broken?

The common signs are a ticking sound at cold start that quiets down as the engine warms, soot streaks around the manifold or the turbo flange, and lost boost. A cracked manifold gives similar clues. If you find one broken stud, plan on replacing the hardware set and the gaskets while the manifold is off.

Do I need an aftermarket exhaust brake on this truck?

Not necessarily. The factory HE351VE turbo already works as an exhaust brake by closing its nozzle to build backpressure. The BD Diesel remote-mount exhaust brake is a separate unit; read its listing and call us to confirm it suits your truck and setup before you buy.

Will a 5.9L Cummins exhaust manifold fit my 6.7L?

No. The 6.7L uses a different manifold casting, and ATS lists its Pulse Flow manifold by engine. Order the part listed for the 6.7L. Studs, bolts and some gasket sets do cover both engines, so check each listing's year range.

Not sure what fits? Call the shop at the number in the header, or use the fitment checker on any product page. We install everything we sell.