2004.5-2007 Dodge 5.9L Cummins Mufflers

Mufflers on the 2004.5-2007 RAM 5.9L Cummins

From 2004.5 on, the 5.9L Cummins left the factory with a 4-inch exhaust and a catalytic converter downstream of the turbo. The muffler sits behind that converter, which is why swapping it is a simple, compliant way to change how the truck sounds. Muffler swaps are the common mild exhaust upgrade on this platform, and several brands build for it. Here we carry MBRP.

What to expect

A muffler is a sound choice, not a power part. On these trucks the stock turbine housing is the biggest restriction in the exhaust, so pipe and muffler changes alone give little gain at stock power. What you get is a different tone. If you want it quieter, start with MBRP's Quiet Tone models.

What we carry: direct-fit vs. universal

The MBRP MK96116 Armor Plus direct-replacement muffler is listed for the 2004.5-2007 5.9L and goes in where the factory muffler came out. The rest are not listed as direct-fit for this truck, so they need to be fitted to your pipe:

• Universal 4-inch and 5-inch 409 stainless mufflers.
• A universal 4-inch Quiet Tone and an Armor Lite 5-inch Quiet Tone.
• The GP290022 Armor Plus 5-inch high-flow muffler.
• The M20681 Armor Lite resonator muffler.
• MBRP diesel resonators in aluminized or stainless.

For other trucks, see our main exhaust page.

Fitment notes

Match the muffler to your pipe size. A stock 2004.5-2007 is 4-inch; if you've installed a 5-inch cat-back, buy 5-inch. Trucks from 2003 and early 2004 have a 3.5-inch downpipe and no converter, a different exhaust from the 2004.5 trucks, so check the build date on a 2004. On a 2007, confirm the 5.9L before ordering, since the 6.7L shared that model year with a different exhaust. Verify by VIN if you're unsure.

Frequently asked questions

Will a new muffler add power to my 5.9L?

Not much. The stock turbine housing is the biggest restriction in this exhaust, so a muffler change alone brings little gain at stock power. Buy it for the sound. It sits behind the factory converter and leaves it in place.

Which muffler bolts in without modification?

The MBRP MK96116 Armor Plus direct-replacement muffler, listed for 2004.5-2007 5.9L trucks. The rest of this section is not listed as direct-fit and needs to be fitted to your pipe. We install what we sell, so the shop can handle a universal fit.

Do I need a 4-inch or a 5-inch muffler?

Match it to your pipe. The factory exhaust on a 2004.5-2007 is 4-inch. If you're running an aftermarket 5-inch cat-back, go 5-inch. MBRP's universal mufflers come in both sizes.

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.